From c93feb5dfc3d5cefa83391ff2e4df7d11ad8e0fa Mon Sep 17 00:00:00 2001
From: James Brunton <jbrunton96@gmail.com>
Date: Wed, 26 Aug 2026 14:09:55 +0000
Subject: [PATCH] Remove a bunch of unnecessary casts from the frontend (#7662)

# Description of Changes
Originally, I wanted to re-enable typed linting on our repo but using
Oxlint this time to avoid the memory and speed issues that ESLint was
causing. Unfortunately, it's not stable enough yet to actually use on
our repo (although it is close, I suspect it'll be stable enough fairly
soon). I was able to remove many of the unnecessary casts that it found
though, so even though this won't be enforced, it's still worth cleaning
up what I've found.
---
 .../config/configSections/TeamSection.tsx     |  8 +++---
 .../core/components/fileEditor/FileEditor.tsx |  7 ++---
 .../components/filesPage/FileDetailsPanel.tsx |  2 +-
 .../core/components/filesPage/FileGrid.tsx    | 12 ++++-----
 .../components/filesPage/FileManagerView.tsx  |  8 +++---
 .../components/filesPage/VersionTimeline.tsx  |  6 ++---
 .../components/filesPage/folderTreeWidth.ts   |  2 +-
 .../mobileSign/MobileDrawCanvas.tsx           |  4 +--
 .../core/components/onboarding/Onboarding.tsx |  3 +--
 .../pageEditor/commands/pageCommands.ts       |  2 +-
 .../shared/superSearch/SuperSearch.test.tsx   |  4 +--
 .../wetSignature/SignatureTypeSelector.tsx    |  2 +-
 .../core/components/toast/ToastContext.tsx    |  9 +++----
 .../components/tools/FullscreenToolList.tsx   | 10 +++----
 .../core/components/tools/RightSidebar.tsx    |  4 +--
 .../core/components/tools/ToolRenderer.tsx    |  4 +--
 .../addPageNumbers/PageNumberPreview.tsx      |  7 +----
 .../addWatermark/WatermarkStyleSettings.tsx   | 16 +++--------
 .../AdjustPageScaleSettings.tsx               |  4 +--
 .../tools/certSign/WetSignatureInput.tsx      |  4 +--
 .../compare/ComparePixelWorkbenchView.tsx     |  2 +-
 .../tools/compare/CompareWorkbenchView.tsx    |  7 +++--
 .../core/components/tools/compare/compare.ts  |  2 +-
 .../hooks/useCompareChangeNavigation.ts       |  6 ++---
 .../tools/compare/hooks/useComparePanZoom.ts  | 10 +++----
 .../hooks/useCompareWorkbenchBarButtons.tsx   |  3 +--
 .../fullscreen/DetailedToolItem.stories.tsx   |  4 +--
 .../tools/overlayPdfs/OverlayPdfsSettings.tsx |  2 +-
 .../pdfTextEditor/PdfTextEditorSidebar.tsx    |  4 +--
 .../tools/shared/ReviewToolStep.tsx           |  9 +++----
 .../src/core/components/tools/showJS/utils.ts |  4 +--
 .../tools/sign/MobileSignatureModal.test.tsx  |  8 +++---
 .../components/tools/sign/SignSettings.tsx    |  6 ++---
 .../tools/toolPicker/ToolButton.tsx           |  4 +--
 .../ValidateSignatureResults.tsx              |  2 +-
 .../file/classificationToolRace.test.ts       |  7 ++---
 .../core/data/usePrototypeToolRegistry.tsx    |  2 +-
 .../useAddPasswordOperation.test.ts           |  2 +-
 .../autoRotate/useAutoRotateOperation.ts      |  3 +--
 .../tools/automate/useAutomateOperation.ts    |  2 +-
 .../hooks/tools/compare/operationUtils.ts     |  6 ++---
 .../tools/compare/useCompareOperation.ts      |  7 +++--
 .../tools/convert/useConvertOperation.ts      | 17 +++---------
 .../core/hooks/tools/shared/toolAutomation.ts |  2 +-
 .../tools/shared/toolOperationDescriptor.ts   |  9 +++----
 .../hooks/tools/shared/toolOperationTypes.ts  |  4 +--
 .../hooks/tools/shared/useToolOperation.ts    | 10 ++-----
 .../core/hooks/tools/useFavoriteToolItems.ts  |  4 +--
 .../utils/signatureStatus.test.ts             |  5 +---
 frontend/editor/src/core/i18n.ts              |  2 +-
 frontend/editor/src/core/setupTests.ts        |  2 +-
 .../src/core/tests/stubbed/settings.spec.ts   |  8 ++----
 frontend/editor/src/core/tools/Compare.tsx    |  8 +++---
 frontend/editor/src/core/tools/SharedSign.tsx |  6 ++---
 .../core/tools/annotate/AnnotationPanel.tsx   | 18 ++++++-------
 .../core/tools/formFill/FormFieldOverlay.tsx  |  2 +-
 .../core/tools/formFill/FormFillContext.tsx   |  2 +-
 .../formFill/providers/PdfiumFormProvider.ts  | 20 +++++---------
 frontend/editor/src/core/ui/Checkbox.tsx      |  4 +--
 .../utils/bulkselection/parseSelection.ts     |  4 +--
 .../src/desktop/hooks/useEndpointConfig.ts    |  9 ++++---
 .../editor/src/portal/auth/saasSupabase.ts    |  2 +-
 .../docs/EndpointReferenceSection.tsx         |  4 +--
 .../pipelines/PipelineStepSettings.test.tsx   |  3 +--
 .../components/policies/PolicySetupWizard.tsx |  2 +-
 .../processor-flow/useFlowParticles.ts        |  5 +---
 .../src/portal/mocks/handlers/policies.ts     |  2 +-
 .../portal/mocks/handlers/procurementSaas.ts  |  2 +-
 .../editor/src/portal/queries/adapters.ts     |  2 +-
 frontend/editor/src/portal/setupTests.ts      |  2 +-
 .../proprietary/auth/springAuthClient.test.ts | 16 +++++------
 .../proprietary/auth/supabase/UseSession.tsx  |  2 +-
 .../policies/policyRunSettles.test.ts         | 27 +++++++++----------
 .../policies/useClientSideClassification.ts   |  6 ++---
 .../components/policies/usePolicyAutoRun.ts   |  4 +--
 .../shared/FileSidebarGroupControls.tsx       |  2 +-
 .../components/shared/InviteMembersModal.tsx  |  2 +-
 .../components/shared/UpgradeBanner.tsx       | 10 ++-----
 .../config/LoginLandingSetting.test.tsx       |  2 +-
 .../AdminConnectionsSection.tsx               |  6 ++---
 .../configSections/AdminUsageSection.tsx      |  6 ++---
 .../configSections/audit/AuditEventsTable.tsx |  8 +++---
 .../configSections/plan/LicenseKeySection.tsx |  2 +-
 .../usage/UsageAnalyticsTable.tsx             |  8 +++---
 .../components/shared/fileSidebarGrouping.tsx |  3 +--
 .../shared/fileSidebarGroupingLogic.ts        |  2 +-
 .../proprietary/hooks/useFolderRunStatuses.ts |  2 +-
 .../editor/src/proprietary/policies/codec.ts  |  6 ++---
 .../src/proprietary/routes/Login.test.tsx     |  3 +--
 .../services/heuristic/heuristicEngine.ts     |  3 +--
 .../services/heuristic/heuristicExtractor.ts  |  3 +--
 .../src/proprietary/services/policyExport.ts  |  2 +-
 .../editor/src/saas/auth/UseSession.test.ts   |  2 +-
 .../components/SignupRequiredBootstrap.tsx    |  8 ++----
 .../saas/components/shared/AppConfigModal.tsx | 18 +++++--------
 .../shared/charts/StackedBarChart.tsx         |  6 ++---
 .../shared/config/configSections/Overview.tsx | 10 +------
 .../components/tools/sign/SignSettings.tsx    |  6 ++---
 .../editor/src/saas/routes/OAuthConsent.tsx   |  5 ++--
 frontend/editor/src/saas/setupTests.ts        |  2 +-
 100 files changed, 217 insertions(+), 345 deletions(-)

diff --git a/frontend/editor/src/cloud/components/shared/config/configSections/TeamSection.tsx b/frontend/editor/src/cloud/components/shared/config/configSections/TeamSection.tsx
index 4eb064d8bf..ab8a184828 100644
--- a/frontend/editor/src/cloud/components/shared/config/configSections/TeamSection.tsx
+++ b/frontend/editor/src/cloud/components/shared/config/configSections/TeamSection.tsx
@@ -360,11 +360,9 @@ const TeamSection: React.FC = () => {
           verticalSpacing="sm"
           withRowBorders
           highlightOnHover
-          style={
-            {
-              "--table-border-color": "var(--mantine-color-gray-3)",
-            } as React.CSSProperties
-          }
+          style={{
+            "--table-border-color": "var(--mantine-color-gray-3)",
+          }}
         >
           <Table.Thead>
             <Table.Tr
diff --git a/frontend/editor/src/core/components/fileEditor/FileEditor.tsx b/frontend/editor/src/core/components/fileEditor/FileEditor.tsx
index 8cfef80d83..1072758275 100644
--- a/frontend/editor/src/core/components/fileEditor/FileEditor.tsx
+++ b/frontend/editor/src/core/components/fileEditor/FileEditor.tsx
@@ -336,7 +336,7 @@ const FileEditor = ({
     (fileId: FileId) => {
       const index = stubsRef.current.findIndex((r) => r.id === fileId);
       if (index !== -1) {
-        setActiveFileId(fileId as string);
+        setActiveFileId(fileId);
         setActiveFileIndex(index);
         navActions.setWorkbench("viewer");
       }
@@ -410,10 +410,7 @@ const FileEditor = ({
                     onUnzipFile={handleUnzipFile}
                     toolMode={toolMode}
                     isSupported={isFileSupported(record.name)}
-                    policies={
-                      policyFileBadges.get(record.id as string) ??
-                      EMPTY_POLICIES
-                    }
+                    policies={policyFileBadges.get(record.id) ?? EMPTY_POLICIES}
                   />
                 );
               })}
diff --git a/frontend/editor/src/core/components/filesPage/FileDetailsPanel.tsx b/frontend/editor/src/core/components/filesPage/FileDetailsPanel.tsx
index 693d8efae7..ff570bbe1d 100644
--- a/frontend/editor/src/core/components/filesPage/FileDetailsPanel.tsx
+++ b/frontend/editor/src/core/components/filesPage/FileDetailsPanel.tsx
@@ -140,7 +140,7 @@ export function FileDetailsPanel({
     return null;
   }
 
-  const single = files.length === 1 ? files[0]! : null;
+  const single = files.length === 1 ? files[0] : null;
   const totalSize = files.reduce((sum, f) => sum + f.size, 0);
   const ext = single ? (single.name.split(".").pop() ?? "").toUpperCase() : "";
   // Files still needing a server upload; drives Save-to-server visibility.
diff --git a/frontend/editor/src/core/components/filesPage/FileGrid.tsx b/frontend/editor/src/core/components/filesPage/FileGrid.tsx
index 40e17dc502..334ad76805 100644
--- a/frontend/editor/src/core/components/filesPage/FileGrid.tsx
+++ b/frontend/editor/src/core/components/filesPage/FileGrid.tsx
@@ -422,7 +422,7 @@ function GridView(props: FileGridProps) {
               parentPath={entry.parentPath}
               isSelected={selectedFileIds.has(entry.file.id)}
               isInWorkspace={
-                activeWorkspaceFileIds?.has(entry.file.id as string) ?? false
+                activeWorkspaceFileIds?.has(entry.file.id) ?? false
               }
               selectedFileIds={selectedFileIds}
               multiSelectActive={selectedFileIds.size >= 2}
@@ -938,7 +938,7 @@ function FileCard({
                 shiftKey: false,
                 ctrlKey: true,
                 metaKey: true,
-              } as unknown as React.MouseEvent);
+              });
             }}
             onChange={() => {
               /* handled by onClick */
@@ -982,7 +982,7 @@ function FileCard({
             ·
           </span>
           <span>{fileDate}</span>
-          <PolicyBadges fileId={file.id as string} />
+          <PolicyBadges fileId={file.id} />
         </div>
       </div>
       <div className="files-page-card-actions">
@@ -1137,7 +1137,7 @@ function ListView(
               parentPath={entry.parentPath}
               isSelected={selectedFileIds.has(entry.file.id)}
               isInWorkspace={
-                activeWorkspaceFileIds?.has(entry.file.id as string) ?? false
+                activeWorkspaceFileIds?.has(entry.file.id) ?? false
               }
               selectedFileIds={selectedFileIds}
               multiSelectActive={selectedFileIds.size >= 2}
@@ -1424,7 +1424,7 @@ function FileRow({
                 shiftKey: false,
                 ctrlKey: true,
                 metaKey: true,
-              } as unknown as React.MouseEvent);
+              });
             }}
             onChange={() => {
               /* handled by onClick */
@@ -1491,7 +1491,7 @@ function FileRow({
           )}
         </span>
         <FileOriginBadge origin={getFileOrigin(file)} compact />
-        <PolicyBadges fileId={file.id as string} />
+        <PolicyBadges fileId={file.id} />
         {isInWorkspace && (
           <span className="files-page-row-open-pill">
             <span className="files-page-card-open-dot" />
diff --git a/frontend/editor/src/core/components/filesPage/FileManagerView.tsx b/frontend/editor/src/core/components/filesPage/FileManagerView.tsx
index 36ffb9c4dc..4665784e79 100644
--- a/frontend/editor/src/core/components/filesPage/FileManagerView.tsx
+++ b/frontend/editor/src/core/components/filesPage/FileManagerView.tsx
@@ -474,7 +474,7 @@ export default function FileManagerView() {
           if (idx >= 0 && lastIdx >= 0) {
             const [a, b] = idx < lastIdx ? [idx, lastIdx] : [lastIdx, idx];
             for (let i = a; i <= b; i += 1) {
-              next.add(visibleFiles[i]!.id);
+              next.add(visibleFiles[i].id);
             }
             return next;
           }
@@ -593,7 +593,7 @@ export default function FileManagerView() {
         });
         // Branch on requested stubs so already-active files still activate.
         if (materialized.length === 1) {
-          setActiveFileId(materialized[0]!.id);
+          setActiveFileId(materialized[0].id);
           navActions.setWorkbench("viewer");
         } else if (materialized.length > 1) {
           navActions.setWorkbench("fileEditor");
@@ -1172,7 +1172,7 @@ export default function FileManagerView() {
                   else if (e.key === "End") next = TAB_DEFS.length - 1;
                   else return;
                   e.preventDefault();
-                  const target = TAB_DEFS[next]!;
+                  const target = TAB_DEFS[next];
                   setCurrentTab(target.id);
                   focusTab(target.id);
                 }}
@@ -1602,7 +1602,7 @@ export default function FileManagerView() {
                         )
                       )
                         return;
-                      setViewMode(v as (typeof FILES_PAGE_VIEW_MODES)[number]);
+                      setViewMode(v);
                     }}
                     aria-label={t("filesPage.viewMode.label", "View mode")}
                     options={[
diff --git a/frontend/editor/src/core/components/filesPage/VersionTimeline.tsx b/frontend/editor/src/core/components/filesPage/VersionTimeline.tsx
index 05c96685b2..f484f936ef 100644
--- a/frontend/editor/src/core/components/filesPage/VersionTimeline.tsx
+++ b/frontend/editor/src/core/components/filesPage/VersionTimeline.tsx
@@ -120,14 +120,14 @@ export function VersionTimeline({
       };
   const rows: Row[] = useMemo(() => {
     if (!collapsible || showAllCollapsed) {
-      return ordered.map((v) => ({ kind: "version", version: v }) as Row);
+      return ordered.map<Row>((v) => ({ kind: "version", version: v }));
     }
     const head = ordered
       .slice(0, 3)
-      .map((v) => ({ kind: "version", version: v }) as Row);
+      .map<Row>((v) => ({ kind: "version", version: v }));
     const tail = ordered
       .slice(-2)
-      .map((v) => ({ kind: "version", version: v }) as Row);
+      .map<Row>((v) => ({ kind: "version", version: v }));
     const hidden = ordered.length - 5;
     return [...head, { kind: "ellipsis", hidden }, ...tail];
   }, [collapsible, showAllCollapsed, ordered]);
diff --git a/frontend/editor/src/core/components/filesPage/folderTreeWidth.ts b/frontend/editor/src/core/components/filesPage/folderTreeWidth.ts
index 4aaf8099ec..a88b0e7f11 100644
--- a/frontend/editor/src/core/components/filesPage/folderTreeWidth.ts
+++ b/frontend/editor/src/core/components/filesPage/folderTreeWidth.ts
@@ -27,7 +27,7 @@ function depthOf(
   let cursor: FolderRecord | undefined = folder;
   while (cursor && cursor.parentFolderId) {
     depth += 1;
-    cursor = byId.get(cursor.parentFolderId as string);
+    cursor = byId.get(cursor.parentFolderId);
     if (depth > 50) break;
   }
   return depth;
diff --git a/frontend/editor/src/core/components/mobileSign/MobileDrawCanvas.tsx b/frontend/editor/src/core/components/mobileSign/MobileDrawCanvas.tsx
index 38c2be8e6c..8461727240 100644
--- a/frontend/editor/src/core/components/mobileSign/MobileDrawCanvas.tsx
+++ b/frontend/editor/src/core/components/mobileSign/MobileDrawCanvas.tsx
@@ -139,9 +139,9 @@ export const MobileDrawCanvas = forwardRef<
     // where the per-frame synthetic event alone would drop curvature.
     const events =
       "getCoalescedEvents" in e.nativeEvent
-        ? (e.nativeEvent as PointerEvent).getCoalescedEvents()
+        ? e.nativeEvent.getCoalescedEvents()
         : [e.nativeEvent as PointerEvent];
-    const rect = (e.currentTarget as HTMLCanvasElement).getBoundingClientRect();
+    const rect = e.currentTarget.getBoundingClientRect();
     for (const ev of events) {
       stroke.points.push({
         x: ev.clientX - rect.left,
diff --git a/frontend/editor/src/core/components/onboarding/Onboarding.tsx b/frontend/editor/src/core/components/onboarding/Onboarding.tsx
index e95aaf57aa..3ce2e2701f 100644
--- a/frontend/editor/src/core/components/onboarding/Onboarding.tsx
+++ b/frontend/editor/src/core/components/onboarding/Onboarding.tsx
@@ -20,7 +20,6 @@ import {
 import { useOnboardingDownload } from "@app/components/onboarding/useOnboardingDownload";
 import {
   SLIDE_DEFINITIONS,
-  type SlideId,
   type ButtonAction,
 } from "@app/components/onboarding/onboardingFlowConfig";
 import ToolPanelModePrompt from "@app/components/tools/ToolPanelModePrompt";
@@ -322,7 +321,7 @@ export default function Onboarding() {
     ) {
       return null;
     }
-    return SLIDE_DEFINITIONS[currentStep.slideId as SlideId];
+    return SLIDE_DEFINITIONS[currentStep.slideId];
   }, [currentStep]);
 
   const currentSlideContent = useMemo(() => {
diff --git a/frontend/editor/src/core/components/pageEditor/commands/pageCommands.ts b/frontend/editor/src/core/components/pageEditor/commands/pageCommands.ts
index db9385fc37..2ce10b929c 100644
--- a/frontend/editor/src/core/components/pageEditor/commands/pageCommands.ts
+++ b/frontend/editor/src/core/components/pageEditor/commands/pageCommands.ts
@@ -244,7 +244,7 @@ export class ReorderPagesCommand extends DOMCommand {
         .map((pageNum) =>
           currentDoc.pages.find((p) => p.pageNumber === pageNum),
         )
-        .filter((page) => page !== undefined) as PDFPage[];
+        .filter((page) => page !== undefined);
 
       const remainingPages = currentDoc.pages.filter(
         (page) => !this.selectedPages!.includes(page.pageNumber),
diff --git a/frontend/editor/src/core/components/shared/superSearch/SuperSearch.test.tsx b/frontend/editor/src/core/components/shared/superSearch/SuperSearch.test.tsx
index f77984f090..931c87197f 100644
--- a/frontend/editor/src/core/components/shared/superSearch/SuperSearch.test.tsx
+++ b/frontend/editor/src/core/components/shared/superSearch/SuperSearch.test.tsx
@@ -84,7 +84,7 @@ function renderSearch(
     <MantineProvider>
       <SuperSearch
         inputId="test-super-search"
-        useResults={useResults as TestUseResultsHook | undefined}
+        useResults={useResults}
         scopes={scopes}
       />
     </MantineProvider>,
@@ -103,7 +103,7 @@ describe("SuperSearch", () => {
       width: 320,
       height: 40,
       toJSON: () => "",
-    } as DOMRect);
+    });
 
     Object.defineProperty(Element.prototype, "scrollIntoView", {
       value: vi.fn(),
diff --git a/frontend/editor/src/core/components/shared/wetSignature/SignatureTypeSelector.tsx b/frontend/editor/src/core/components/shared/wetSignature/SignatureTypeSelector.tsx
index 7b4950f4aa..5cc14fcf3c 100644
--- a/frontend/editor/src/core/components/shared/wetSignature/SignatureTypeSelector.tsx
+++ b/frontend/editor/src/core/components/shared/wetSignature/SignatureTypeSelector.tsx
@@ -19,7 +19,7 @@ export const SignatureTypeSelector: React.FC<SignatureTypeSelectorProps> = ({
   return (
     <SegmentedControl
       value={value}
-      onChange={(val) => onChange(val as SignatureType)}
+      onChange={(val) => onChange(val)}
       options={[
         {
           value: "draw",
diff --git a/frontend/editor/src/core/components/toast/ToastContext.tsx b/frontend/editor/src/core/components/toast/ToastContext.tsx
index a300dc1791..4fcc6d8b10 100644
--- a/frontend/editor/src/core/components/toast/ToastContext.tsx
+++ b/frontend/editor/src/core/components/toast/ToastContext.tsx
@@ -93,7 +93,7 @@ export function ToastProvider({ children }: { children: React.ReactNode }) {
               ? true
               : false,
         createdAt: Date.now(),
-      } as ToastInstance;
+      };
       setToasts((prev) => {
         // Coalesce duplicates by alertType + title + body text if no explicit id was provided
         if (!options.id) {
@@ -138,7 +138,7 @@ export function ToastProvider({ children }: { children: React.ReactNode }) {
           ...t,
           ...updates,
           progress,
-        } as ToastInstance;
+        };
 
         // Detect completion but do not auto-flip to success.
         // Callers (e.g., compare workbench) explicitly set alertType when done.
@@ -197,9 +197,8 @@ export function ToastProvider({ children }: { children: React.ReactNode }) {
         ),
       );
     };
-    window.addEventListener("toast:toggle", handler as EventListener);
-    return () =>
-      window.removeEventListener("toast:toggle", handler as EventListener);
+    window.addEventListener("toast:toggle", handler);
+    return () => window.removeEventListener("toast:toggle", handler);
   }, []);
 
   return (
diff --git a/frontend/editor/src/core/components/tools/FullscreenToolList.tsx b/frontend/editor/src/core/components/tools/FullscreenToolList.tsx
index 5296e21299..85a306c476 100644
--- a/frontend/editor/src/core/components/tools/FullscreenToolList.tsx
+++ b/frontend/editor/src/core/components/tools/FullscreenToolList.tsx
@@ -108,7 +108,7 @@ const FullscreenToolList = ({
         window.open(tool.link, "_blank", "noopener,noreferrer");
         return;
       }
-      onSelect(id as ToolId);
+      onSelect(id);
     };
 
     if (showDescriptions) {
@@ -274,15 +274,11 @@ const FullscreenToolList = ({
 
             {showDescriptions ? (
               <div className="tool-panel__fullscreen-grid tool-panel__fullscreen-grid--detailed">
-                {tools.map(({ id, tool }) =>
-                  renderToolItem(id as ToolId, tool),
-                )}
+                {tools.map(({ id, tool }) => renderToolItem(id, tool))}
               </div>
             ) : (
               <div className="tool-panel__fullscreen-list">
-                {tools.map(({ id, tool }) =>
-                  renderToolItem(id as ToolId, tool),
-                )}
+                {tools.map(({ id, tool }) => renderToolItem(id, tool))}
               </div>
             )}
           </section>
diff --git a/frontend/editor/src/core/components/tools/RightSidebar.tsx b/frontend/editor/src/core/components/tools/RightSidebar.tsx
index a4bdbced7e..d66d30c442 100644
--- a/frontend/editor/src/core/components/tools/RightSidebar.tsx
+++ b/frontend/editor/src/core/components/tools/RightSidebar.tsx
@@ -108,7 +108,7 @@ export default function RightSidebar() {
 
   const activeTool: ToolRegistryEntry | null =
     inToolView && selectedToolKey
-      ? (toolRegistry[selectedToolKey as ToolId] ?? null)
+      ? (toolRegistry[selectedToolKey] ?? null)
       : null;
 
   const expandedWidth = "18.5rem";
@@ -131,7 +131,7 @@ export default function RightSidebar() {
     const items: Array<{ id: ToolId; tool: ToolRegistryEntry }> = [];
     collapsedQuickSection.subcategories.forEach((sc: SubcategoryGroup) =>
       sc.tools.forEach((entry) =>
-        items.push({ id: entry.id as ToolId, tool: entry.tool }),
+        items.push({ id: entry.id, tool: entry.tool }),
       ),
     );
     return items;
diff --git a/frontend/editor/src/core/components/tools/ToolRenderer.tsx b/frontend/editor/src/core/components/tools/ToolRenderer.tsx
index 1429231ab7..4c99afbca2 100644
--- a/frontend/editor/src/core/components/tools/ToolRenderer.tsx
+++ b/frontend/editor/src/core/components/tools/ToolRenderer.tsx
@@ -19,9 +19,7 @@ const ToolRenderer = ({
   // Get the tool from context (instead of direct hook call)
   const { toolRegistry } = useToolWorkflow();
   const selectedTool =
-    selectedToolKey in toolRegistry
-      ? toolRegistry[selectedToolKey as ToolId]
-      : undefined;
+    selectedToolKey in toolRegistry ? toolRegistry[selectedToolKey] : undefined;
 
   // Handle tools that only work in workbenches (read, multiTool)
   if (selectedTool && !selectedTool.component && selectedTool.workbench) {
diff --git a/frontend/editor/src/core/components/tools/addPageNumbers/PageNumberPreview.tsx b/frontend/editor/src/core/components/tools/addPageNumbers/PageNumberPreview.tsx
index 6e35b286a9..9991c4b849 100644
--- a/frontend/editor/src/core/components/tools/addPageNumbers/PageNumberPreview.tsx
+++ b/frontend/editor/src/core/components/tools/addPageNumbers/PageNumberPreview.tsx
@@ -261,12 +261,7 @@ export default function PageNumberPreview({
                   variant="tertiary"
                   key={idx}
                   className={`${styles.gridTile} ${selected || hoverTile === idx ? styles.gridTileSelected : ""} ${hoverTile === idx ? styles.gridTileHovered : ""}`}
-                  onClick={() =>
-                    onParameterChange(
-                      "position",
-                      idx as AddPageNumbersParameters["position"],
-                    )
-                  }
+                  onClick={() => onParameterChange("position", idx)}
                   onMouseEnter={() => setHoverTile(idx)}
                   onMouseLeave={() => setHoverTile(null)}
                   style={{
diff --git a/frontend/editor/src/core/components/tools/addWatermark/WatermarkStyleSettings.tsx b/frontend/editor/src/core/components/tools/addWatermark/WatermarkStyleSettings.tsx
index 1d9dad2995..c9ce1ca1bd 100644
--- a/frontend/editor/src/core/components/tools/addWatermark/WatermarkStyleSettings.tsx
+++ b/frontend/editor/src/core/components/tools/addWatermark/WatermarkStyleSettings.tsx
@@ -36,9 +36,7 @@ const WatermarkStyleSettings = ({
           onChange={(value) =>
             onParameterChange(
               "rotation",
-              typeof value === "number"
-                ? value
-                : parseInt(value as string, 10) || 0,
+              typeof value === "number" ? value : parseInt(value, 10) || 0,
             )
           }
           min={-360}
@@ -55,9 +53,7 @@ const WatermarkStyleSettings = ({
           onChange={(value) =>
             onParameterChange(
               "opacity",
-              typeof value === "number"
-                ? value
-                : parseInt(value as string, 10) || 50,
+              typeof value === "number" ? value : parseInt(value, 10) || 50,
             )
           }
           min={0}
@@ -77,9 +73,7 @@ const WatermarkStyleSettings = ({
           onChange={(value) =>
             onParameterChange(
               "widthSpacer",
-              typeof value === "number"
-                ? value
-                : parseInt(value as string, 10) || 50,
+              typeof value === "number" ? value : parseInt(value, 10) || 50,
             )
           }
           min={0}
@@ -96,9 +90,7 @@ const WatermarkStyleSettings = ({
           onChange={(value) =>
             onParameterChange(
               "heightSpacer",
-              typeof value === "number"
-                ? value
-                : parseInt(value as string, 10) || 50,
+              typeof value === "number" ? value : parseInt(value, 10) || 50,
             )
           }
           min={0}
diff --git a/frontend/editor/src/core/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx b/frontend/editor/src/core/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
index aeb874b58e..e2bf0a8466 100644
--- a/frontend/editor/src/core/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
+++ b/frontend/editor/src/core/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
@@ -103,9 +103,7 @@ const AdjustPageScaleSettings = ({
       <SegmentedControl
         aria-label={t("adjustPageScale.orientation.label", "Page orientation")}
         value={parameters.orientation}
-        onChange={(value) =>
-          onParameterChange("orientation", value as Orientation)
-        }
+        onChange={(value) => onParameterChange("orientation", value)}
         options={orientationOptions}
         fullWidth
       />
diff --git a/frontend/editor/src/core/components/tools/certSign/WetSignatureInput.tsx b/frontend/editor/src/core/components/tools/certSign/WetSignatureInput.tsx
index f87fda19fe..af1913baa7 100644
--- a/frontend/editor/src/core/components/tools/certSign/WetSignatureInput.tsx
+++ b/frontend/editor/src/core/components/tools/certSign/WetSignatureInput.tsx
@@ -238,9 +238,7 @@ const WetSignatureInput = ({
         <SegmentedControl
           value={signatureType}
           fullWidth
-          onChange={(value) =>
-            handleSignatureTypeChange(value as SignatureType)
-          }
+          onChange={(value) => handleSignatureTypeChange(value)}
           options={[
             { label: t("sign.type.canvas", "Draw"), value: "canvas", disabled },
             { label: t("sign.type.image", "Upload"), value: "image", disabled },
diff --git a/frontend/editor/src/core/components/tools/compare/ComparePixelWorkbenchView.tsx b/frontend/editor/src/core/components/tools/compare/ComparePixelWorkbenchView.tsx
index d45ccd75a0..35b3a7e0f4 100644
--- a/frontend/editor/src/core/components/tools/compare/ComparePixelWorkbenchView.tsx
+++ b/frontend/editor/src/core/components/tools/compare/ComparePixelWorkbenchView.tsx
@@ -170,7 +170,7 @@ const ComparePixelWorkbenchView = ({
         <SegmentedControl
           size="sm"
           value={viewMode}
-          onChange={(value) => setViewMode(value as PixelViewMode)}
+          onChange={(value) => setViewMode(value)}
           options={[
             {
               value: "side-by-side",
diff --git a/frontend/editor/src/core/components/tools/compare/CompareWorkbenchView.tsx b/frontend/editor/src/core/components/tools/compare/CompareWorkbenchView.tsx
index 1df0f1c14a..5470e3ac8c 100644
--- a/frontend/editor/src/core/components/tools/compare/CompareWorkbenchView.tsx
+++ b/frontend/editor/src/core/components/tools/compare/CompareWorkbenchView.tsx
@@ -28,7 +28,6 @@ import {
   updateToastProgress,
   dismissToast,
 } from "@app/components/toast";
-import type { ToastLocation } from "@app/components/toast/types";
 
 interface CompareWorkbenchViewProps {
   data: CompareWorkbenchData | null;
@@ -323,7 +322,7 @@ const CompareTextWorkbenchView = ({ data }: CompareTextWorkbenchViewProps) => {
             "At least one of these PDFs are very large, scrolling won't be smooth until the rendering is complete",
           ),
           body: `${countsText} ${t("compare.rendering.pagesRendered", "pages rendered")}`,
-          location: "bottom-right" as ToastLocation,
+          location: "bottom-right",
           isPersistentPopup: true,
           durationMs: 0,
           expandable: false,
@@ -337,7 +336,7 @@ const CompareTextWorkbenchView = ({ data }: CompareTextWorkbenchViewProps) => {
             "At least one of these PDFs are very large, scrolling won't be smooth until the rendering is complete",
           ),
           body: `${countsText} ${t("compare.rendering.pagesRendered", "pages rendered")}`,
-          location: "bottom-right" as ToastLocation,
+          location: "bottom-right",
           isPersistentPopup: true,
           alertType: "neutral", // ensure it stays neutral until completion
         });
@@ -452,7 +451,7 @@ const CompareTextWorkbenchView = ({ data }: CompareTextWorkbenchViewProps) => {
             "compare.rendering.pageNotReadyBody",
             "Some pages are still rendering. Navigation will snap once they are ready.",
           ),
-          location: "bottom-right" as ToastLocation,
+          location: "bottom-right",
           isPersistentPopup: false,
           durationMs: 2500,
         });
diff --git a/frontend/editor/src/core/components/tools/compare/compare.ts b/frontend/editor/src/core/components/tools/compare/compare.ts
index 30d0c42304..b157745307 100644
--- a/frontend/editor/src/core/components/tools/compare/compare.ts
+++ b/frontend/editor/src/core/components/tools/compare/compare.ts
@@ -186,7 +186,7 @@ export const getFileFromSelection = (
 ): StirlingFile | null => {
   if (explicit) return explicit;
   if (!fileId) return null;
-  return (selectors.getFile(fileId) as StirlingFile | undefined | null) ?? null;
+  return selectors.getFile(fileId) ?? null;
 };
 
 export const getStubFromSelection = (
diff --git a/frontend/editor/src/core/components/tools/compare/hooks/useCompareChangeNavigation.ts b/frontend/editor/src/core/components/tools/compare/hooks/useCompareChangeNavigation.ts
index d7d8e95635..e56187f5f2 100644
--- a/frontend/editor/src/core/components/tools/compare/hooks/useCompareChangeNavigation.ts
+++ b/frontend/editor/src/core/components/tools/compare/hooks/useCompareChangeNavigation.ts
@@ -79,7 +79,7 @@ export const useCompareChangeNavigation = (
         const inner = anchor.closest(
           ".compare-diff-page__inner",
         ) as HTMLElement | null;
-        const topPercent = parseFloat((anchor as HTMLElement).style.top || "0");
+        const topPercent = parseFloat(anchor.style.top || "0");
         if (pageEl && inner && !Number.isNaN(topPercent)) {
           const innerRect = inner.getBoundingClientRect();
           const innerHeight = Math.max(1, innerRect.height);
@@ -156,9 +156,7 @@ export const useCompareChangeNavigation = (
             ".compare-diff-page",
           ) as HTMLElement | null;
           const pageNumAttr = pageEl?.getAttribute("data-page-number");
-          const topPercent = parseFloat(
-            (anchor as HTMLElement).style.top || "0",
-          );
+          const topPercent = parseFloat(anchor.style.top || "0");
           if (pageNumAttr) {
             const peerPageEl = peer.querySelector(
               `.compare-diff-page[data-page-number="${pageNumAttr}"]`,
diff --git a/frontend/editor/src/core/components/tools/compare/hooks/useComparePanZoom.ts b/frontend/editor/src/core/components/tools/compare/hooks/useComparePanZoom.ts
index bac47de952..d44c55e1ec 100644
--- a/frontend/editor/src/core/components/tools/compare/hooks/useComparePanZoom.ts
+++ b/frontend/editor/src/core/components/tools/compare/hooks/useComparePanZoom.ts
@@ -323,7 +323,7 @@ export const useComparePanZoom = ({
       const pages = getPagesForPane(pane);
       const rotation = pages[0]?.rotation ?? 0;
       const normalized = ((rotation % 360) + 360) % 360;
-      return normalized as 0 | 90 | 180 | 270 | number;
+      return normalized;
     },
     [getPagesForPane],
   );
@@ -656,7 +656,7 @@ export const useComparePanZoom = ({
       };
       edgeOverscrollRef.current[pane] = 0;
       lastActivePaneRef.current = pane;
-      (container as HTMLDivElement).style.cursor = "grabbing";
+      container.style.cursor = "grabbing";
     },
     [isPanMode, baseZoom, comparisonZoom, basePan, comparisonPan],
   );
@@ -700,11 +700,7 @@ export const useComparePanZoom = ({
         : comparisonScrollRef.current;
     if (sourceEl) {
       const zoom = drag.source === "base" ? baseZoom : comparisonZoom;
-      (sourceEl as HTMLDivElement).style.cursor = isPanMode
-        ? zoom > 1
-          ? "grab"
-          : "auto"
-        : "";
+      sourceEl.style.cursor = isPanMode ? (zoom > 1 ? "grab" : "auto") : "";
     }
     panDragRef.current.active = false;
     panDragRef.current.source = null;
diff --git a/frontend/editor/src/core/components/tools/compare/hooks/useCompareWorkbenchBarButtons.tsx b/frontend/editor/src/core/components/tools/compare/hooks/useCompareWorkbenchBarButtons.tsx
index 3ddbbbf3da..076ac877d5 100644
--- a/frontend/editor/src/core/components/tools/compare/hooks/useCompareWorkbenchBarButtons.tsx
+++ b/frontend/editor/src/core/components/tools/compare/hooks/useCompareWorkbenchBarButtons.tsx
@@ -3,7 +3,6 @@ import type React from "react";
 import { useTranslation } from "react-i18next";
 import LocalIcon from "@app/components/shared/LocalIcon";
 import { alert } from "@app/components/toast";
-import type { ToastLocation } from "@app/components/toast/types";
 import type { WorkbenchBarButtonWithAction } from "@app/hooks/useWorkbenchBarButtons";
 import { useIsMobile } from "@app/hooks/useIsMobile";
 
@@ -179,7 +178,7 @@ export const useCompareWorkbenchBarButtons = ({
                   "Tip: Arrow Up/Down scroll both panes when unlinked is off.",
                 ),
                 durationMs: 5000,
-                location: "bottom-center" as ToastLocation,
+                location: "bottom-center",
                 expandable: false,
               });
             }
diff --git a/frontend/editor/src/core/components/tools/fullscreen/DetailedToolItem.stories.tsx b/frontend/editor/src/core/components/tools/fullscreen/DetailedToolItem.stories.tsx
index cd443e248a..901824aaf6 100644
--- a/frontend/editor/src/core/components/tools/fullscreen/DetailedToolItem.stories.tsx
+++ b/frontend/editor/src/core/components/tools/fullscreen/DetailedToolItem.stories.tsx
@@ -94,10 +94,10 @@ type Story = StoryObj<typeof meta>;
 
 /** An available tool rendered in its default, unselected state. */
 export const Default: Story = {
-  render: () => <ToolItemDemo toolId={"split" as ToolId} />,
+  render: () => <ToolItemDemo toolId={"split"} />,
 };
 
 /** The active tool in the panel — highlighted selected state. */
 export const Selected: Story = {
-  render: () => <ToolItemDemo toolId={"split" as ToolId} isSelected />,
+  render: () => <ToolItemDemo toolId={"split"} isSelected />,
 };
diff --git a/frontend/editor/src/core/components/tools/overlayPdfs/OverlayPdfsSettings.tsx b/frontend/editor/src/core/components/tools/overlayPdfs/OverlayPdfsSettings.tsx
index e7246bb4e3..8df455182e 100644
--- a/frontend/editor/src/core/components/tools/overlayPdfs/OverlayPdfsSettings.tsx
+++ b/frontend/editor/src/core/components/tools/overlayPdfs/OverlayPdfsSettings.tsx
@@ -137,7 +137,7 @@ export default function OverlayPdfsSettings({
         <SegmentedControl
           value={String(parameters.overlayPosition)}
           onChange={(v) =>
-            onParameterChange("overlayPosition", (v === "1" ? 1 : 0) as 0 | 1)
+            onParameterChange("overlayPosition", v === "1" ? 1 : 0)
           }
           options={[
             {
diff --git a/frontend/editor/src/core/components/tools/pdfTextEditor/PdfTextEditorSidebar.tsx b/frontend/editor/src/core/components/tools/pdfTextEditor/PdfTextEditorSidebar.tsx
index 1892aaa7f3..a0ce9fc362 100644
--- a/frontend/editor/src/core/components/tools/pdfTextEditor/PdfTextEditorSidebar.tsx
+++ b/frontend/editor/src/core/components/tools/pdfTextEditor/PdfTextEditorSidebar.tsx
@@ -279,9 +279,7 @@ const PdfTextEditorSidebar = ({ data }: PdfTextEditorSidebarProps) => {
                   </Text>
                   <SegmentedControl
                     value={externalGroupingMode}
-                    onChange={(value) =>
-                      handleModeChangeRequest(value as GroupingMode)
-                    }
+                    onChange={(value) => handleModeChangeRequest(value)}
                     options={[
                       {
                         label: t("pdfTextEditor.groupingMode.auto", "Auto"),
diff --git a/frontend/editor/src/core/components/tools/shared/ReviewToolStep.tsx b/frontend/editor/src/core/components/tools/shared/ReviewToolStep.tsx
index 7918bac7ca..ef596c2a0d 100644
--- a/frontend/editor/src/core/components/tools/shared/ReviewToolStep.tsx
+++ b/frontend/editor/src/core/components/tools/shared/ReviewToolStep.tsx
@@ -12,7 +12,6 @@ import { useFileActionTerminology } from "@app/hooks/useFileActionTerminology";
 import { useFileActionIcons } from "@app/hooks/useFileActionIcons";
 import { saveOperationResults } from "@app/services/operationResultsSaveService";
 import { useFileActions, useFileSelectors } from "@app/contexts/FileContext";
-import { FileId } from "@app/types/fileContext";
 import i18n from "@app/i18n";
 
 export interface ReviewToolStepProps<TParams = unknown> {
@@ -65,11 +64,11 @@ function ReviewStepContent<TParams = unknown>({
         downloadFilename: operation.downloadFilename || "download",
         downloadLocalPath: operation.downloadLocalPath,
         outputFileIds: operation.outputFileIds,
-        getFile: (fileId) => selectors.getFile(fileId as FileId),
-        getStub: (fileId) => selectors.getStirlingFileStub(fileId as FileId),
+        getFile: (fileId) => selectors.getFile(fileId),
+        getStub: (fileId) => selectors.getStirlingFileStub(fileId),
         markSaved: (fileId, savedPath) => {
-          const stub = selectors.getStirlingFileStub(fileId as FileId);
-          fileActions.updateStirlingFileStub(fileId as FileId, {
+          const stub = selectors.getStirlingFileStub(fileId);
+          fileActions.updateStirlingFileStub(fileId, {
             localFilePath: stub?.localFilePath ?? savedPath,
             isDirty: false,
           });
diff --git a/frontend/editor/src/core/components/tools/showJS/utils.ts b/frontend/editor/src/core/components/tools/showJS/utils.ts
index e946ec271e..7c6530c21b 100644
--- a/frontend/editor/src/core/components/tools/showJS/utils.ts
+++ b/frontend/editor/src/core/components/tools/showJS/utils.ts
@@ -186,7 +186,7 @@ export function tokenizeToLines(
     }
 
     if (isStringDelimiter) {
-      startString(ch as '"' | "'" | "`");
+      startString(ch);
       continue;
     }
 
@@ -312,7 +312,7 @@ export function computeBlocks(
       continue;
     }
     if (isStringDelimiter) {
-      startString(ch as '"' | "'" | "`");
+      startString(ch);
       continue;
     }
     if (isOpenBrace) {
diff --git a/frontend/editor/src/core/components/tools/sign/MobileSignatureModal.test.tsx b/frontend/editor/src/core/components/tools/sign/MobileSignatureModal.test.tsx
index c8607d55c4..4f68e7c68c 100644
--- a/frontend/editor/src/core/components/tools/sign/MobileSignatureModal.test.tsx
+++ b/frontend/editor/src/core/components/tools/sign/MobileSignatureModal.test.tsx
@@ -52,9 +52,9 @@ function primeSession(
   mockedApi.post.mockResolvedValue({
     status: 200,
     data: SESSION_INFO,
-  } as never);
-  mockedApi.delete.mockResolvedValue({ status: 200 } as never);
-  mockedApi.get.mockImplementation(((url: string, config?: unknown) => {
+  });
+  mockedApi.delete.mockResolvedValue({ status: 200 });
+  mockedApi.get.mockImplementation((url: string, config?: unknown) => {
     if (url.includes("/files/")) {
       return Promise.resolve({ status: 200, data: { files } } as never);
     }
@@ -70,7 +70,7 @@ function primeSession(
       } as never);
     }
     return Promise.reject(new Error(`unexpected GET ${url}`));
-  }) as never);
+  });
 }
 
 function renderModal(
diff --git a/frontend/editor/src/core/components/tools/sign/SignSettings.tsx b/frontend/editor/src/core/components/tools/sign/SignSettings.tsx
index 4aa9f8ffd3..1d78343c79 100644
--- a/frontend/editor/src/core/components/tools/sign/SignSettings.tsx
+++ b/frontend/editor/src/core/components/tools/sign/SignSettings.tsx
@@ -519,7 +519,7 @@ const SignSettings = ({
       return;
     }
     const nextSource = allowedSignatureSources.includes(
-      parameters.signatureType as SignatureSource,
+      parameters.signatureType,
     )
       ? (parameters.signatureType as SignatureSource)
       : effectiveDefaultSource;
@@ -1282,9 +1282,7 @@ const SignSettings = ({
           <SegmentedControl
             value={signatureSource}
             fullWidth
-            onChange={(value) =>
-              handleSignatureSourceChange(value as SignatureSource)
-            }
+            onChange={(value) => handleSignatureSourceChange(value)}
             options={sourceOptions}
           />
         )}
diff --git a/frontend/editor/src/core/components/tools/toolPicker/ToolButton.tsx b/frontend/editor/src/core/components/tools/toolPicker/ToolButton.tsx
index 4792fd721a..8daf2cb019 100644
--- a/frontend/editor/src/core/components/tools/toolPicker/ToolButton.tsx
+++ b/frontend/editor/src/core/components/tools/toolPicker/ToolButton.tsx
@@ -74,7 +74,7 @@ const ToolButton: React.FC<ToolButtonProps> = ({
   const { hotkeys } = useHotkeys();
   const binding = hotkeys[id];
   const { getToolNavigation } = useToolNavigation();
-  const fav = isFavorite(id as ToolId);
+  const fav = isFavorite(id);
 
   // Check if this tool will route to SaaS backend (desktop only)
   const rawEndpoint = tool.operationConfig?.endpoint;
@@ -308,7 +308,7 @@ const ToolButton: React.FC<ToolButtonProps> = ({
     hasStars && !visuallyUnavailable ? (
       <FavoriteStar
         isFavorite={fav}
-        onToggle={() => toggleFavorite(id as ToolId)}
+        onToggle={() => toggleFavorite(id)}
         className="tool-button-star"
         size="xs"
       />
diff --git a/frontend/editor/src/core/components/tools/validateSignature/ValidateSignatureResults.tsx b/frontend/editor/src/core/components/tools/validateSignature/ValidateSignatureResults.tsx
index 22020ac6dc..23a9d9e949 100644
--- a/frontend/editor/src/core/components/tools/validateSignature/ValidateSignatureResults.tsx
+++ b/frontend/editor/src/core/components/tools/validateSignature/ValidateSignatureResults.tsx
@@ -294,7 +294,7 @@ const ValidateSignatureResults = ({
         </Text>
         <SegmentedControl
           value={selectedType}
-          onChange={(v) => setSelectedType(v as "pdf" | "csv" | "json")}
+          onChange={(v) => setSelectedType(v)}
           options={downloadTypeOptions}
         />
         <Button
diff --git a/frontend/editor/src/core/contexts/file/classificationToolRace.test.ts b/frontend/editor/src/core/contexts/file/classificationToolRace.test.ts
index faf6501a0c..21efc2234f 100644
--- a/frontend/editor/src/core/contexts/file/classificationToolRace.test.ts
+++ b/frontend/editor/src/core/contexts/file/classificationToolRace.test.ts
@@ -35,10 +35,7 @@ function stateWith(...stubs: StirlingFileStub[]): FileContextState {
   return {
     files: {
       ids: stubs.map((s) => s.id),
-      byId: Object.fromEntries(stubs.map((s) => [s.id, s])) as Record<
-        FileId,
-        StirlingFileStub
-      >,
+      byId: Object.fromEntries(stubs.map((s) => [s.id, s])),
     },
     pinnedFiles: new Set<FileId>(),
     ui: {
@@ -153,7 +150,7 @@ describe("classification landing vs a manually-run tool", () => {
         versionNumber: 7,
         thumbnailUrl: "blob:thumb",
         isPinned: true,
-      } as Partial<StirlingFileStub>),
+      }),
     );
 
     s = fileContextReducer(s, classify("out"));
diff --git a/frontend/editor/src/core/data/usePrototypeToolRegistry.tsx b/frontend/editor/src/core/data/usePrototypeToolRegistry.tsx
index 6a3279196e..b4da797a14 100644
--- a/frontend/editor/src/core/data/usePrototypeToolRegistry.tsx
+++ b/frontend/editor/src/core/data/usePrototypeToolRegistry.tsx
@@ -11,5 +11,5 @@ import { type PrototypeToolRegistry } from "@app/data/toolsTaxonomy";
 
 // Empty hook that returns an empty registry (overridden in the prototypes overlay).
 export function usePrototypeToolRegistry(): PrototypeToolRegistry {
-  return useMemo(() => ({}) as PrototypeToolRegistry, []);
+  return useMemo(() => ({}), []);
 }
diff --git a/frontend/editor/src/core/hooks/tools/addPassword/useAddPasswordOperation.test.ts b/frontend/editor/src/core/hooks/tools/addPassword/useAddPasswordOperation.test.ts
index 28e8e1baa6..364f2ec3de 100644
--- a/frontend/editor/src/core/hooks/tools/addPassword/useAddPasswordOperation.test.ts
+++ b/frontend/editor/src/core/hooks/tools/addPassword/useAddPasswordOperation.test.ts
@@ -152,7 +152,7 @@ describe("addPassword mappers", () => {
     // undefined: the settings UI calls keyLength.toString() on it.
     const restored = addPasswordFromApiParams({
       password: "user-pw",
-    } as never);
+    });
     expect(restored.keyLength).toBe(128);
   });
 
diff --git a/frontend/editor/src/core/hooks/tools/autoRotate/useAutoRotateOperation.ts b/frontend/editor/src/core/hooks/tools/autoRotate/useAutoRotateOperation.ts
index fde4ae1eca..02c81a9483 100644
--- a/frontend/editor/src/core/hooks/tools/autoRotate/useAutoRotateOperation.ts
+++ b/frontend/editor/src/core/hooks/tools/autoRotate/useAutoRotateOperation.ts
@@ -22,7 +22,6 @@ import type {
 } from "@app/hooks/tools/shared/toolApiMapping";
 import {
   AutoRotateParameters,
-  AutoRotateDetectionMode,
   defaultParameters,
   validateAutoRotateParameters,
 } from "@app/hooks/tools/autoRotate/useAutoRotateParameters";
@@ -50,7 +49,7 @@ export const autoRotateToApiParams = (
 export const autoRotateFromApiParams = (
   apiParams: AutoRotateApiParams,
 ): Partial<AutoRotateParameters> => ({
-  detectionMode: apiParams.detectionMode as AutoRotateDetectionMode,
+  detectionMode: apiParams.detectionMode,
   confidenceThreshold: apiParams.confidenceThreshold,
   inferUndetected: apiParams.inferUndetected,
 });
diff --git a/frontend/editor/src/core/hooks/tools/automate/useAutomateOperation.ts b/frontend/editor/src/core/hooks/tools/automate/useAutomateOperation.ts
index d1d6436fa9..4a96532321 100644
--- a/frontend/editor/src/core/hooks/tools/automate/useAutomateOperation.ts
+++ b/frontend/editor/src/core/hooks/tools/automate/useAutomateOperation.ts
@@ -24,7 +24,7 @@ export function useAutomateOperation() {
 
       // Execute the automation sequence and return the final results
       const finalResults = await executeAutomationSequence(
-        params.automationConfig!,
+        params.automationConfig,
         files,
         toolRegistry,
         (stepIndex: number, operationName: string) => {
diff --git a/frontend/editor/src/core/hooks/tools/compare/operationUtils.ts b/frontend/editor/src/core/hooks/tools/compare/operationUtils.ts
index 832eaba560..78d651c6d9 100644
--- a/frontend/editor/src/core/hooks/tools/compare/operationUtils.ts
+++ b/frontend/editor/src/core/hooks/tools/compare/operationUtils.ts
@@ -358,7 +358,7 @@ export const extractContentFromPdf = async (
           .trim();
 
       const isParagraphBreak = (curr: TextItem, prev: TextItem | null) => {
-        const hasHardBreak = "hasEOL" in curr && (curr as TextItem).hasEOL;
+        const hasHardBreak = "hasEOL" in curr && curr.hasEOL;
         if (hasHardBreak) return true;
         if (!prev) return false;
         const prevY = prev.transform[5];
@@ -624,7 +624,7 @@ export const extractContentFromPdf = async (
           paragraphBuffer = appendWord(paragraphBuffer, normalizedWord);
         }
 
-        if (isParagraphBreak(item as TextItem, prevItem)) {
+        if (isParagraphBreak(item, prevItem)) {
           if (paragraphBuffer.trim().length > 0) {
             paragraphs.push({
               page: pageIndex,
@@ -641,7 +641,7 @@ export const extractContentFromPdf = async (
           });
           paragraphIndex += 1;
         }
-        prevItem = item as TextItem;
+        prevItem = item;
       }
 
       if (paragraphBuffer.trim().length > 0) {
diff --git a/frontend/editor/src/core/hooks/tools/compare/useCompareOperation.ts b/frontend/editor/src/core/hooks/tools/compare/useCompareOperation.ts
index 3a40d9b699..73667946eb 100644
--- a/frontend/editor/src/core/hooks/tools/compare/useCompareOperation.ts
+++ b/frontend/editor/src/core/hooks/tools/compare/useCompareOperation.ts
@@ -28,7 +28,6 @@ import {
   filterTokensForDiff,
 } from "@app/hooks/tools/compare/operationUtils";
 import { alert, dismissToast } from "@app/components/toast";
-import type { ToastLocation } from "@app/components/toast/types";
 import CompareWorkerCtor from "@app/workers/compareWorker?worker";
 const LONG_RUNNING_PAGE_THRESHOLD = 2000;
 
@@ -406,7 +405,7 @@ export const useCompareOperation = (): CompareOperationHook => {
               "compare.longJob.body",
               "These PDFs together exceed 2,000 pages. Processing can take several minutes.",
             ),
-            location: "bottom-right" as ToastLocation,
+            location: "bottom-right",
             isPersistentPopup: true,
             expandable: false,
           });
@@ -435,7 +434,7 @@ export const useCompareOperation = (): CompareOperationHook => {
               "compare.earlyDissimilarity.body",
               "We're seeing very few similarities so far. You can stop the comparison if these aren't related documents.",
             ),
-            location: "bottom-right" as ToastLocation,
+            location: "bottom-right",
             isPersistentPopup: true,
             expandable: false,
             buttonText: t(
@@ -635,7 +634,7 @@ export const useCompareOperation = (): CompareOperationHook => {
           alertType: "warning",
           title: t("compare.error.title", "Comparison failed"),
           body: resolvedMessage,
-          location: "bottom-right" as ToastLocation,
+          location: "bottom-right",
         });
       } finally {
         const duration = performance.now() - operationStart;
diff --git a/frontend/editor/src/core/hooks/tools/convert/useConvertOperation.ts b/frontend/editor/src/core/hooks/tools/convert/useConvertOperation.ts
index 554946cce7..4d54b438f4 100644
--- a/frontend/editor/src/core/hooks/tools/convert/useConvertOperation.ts
+++ b/frontend/editor/src/core/hooks/tools/convert/useConvertOperation.ts
@@ -383,7 +383,7 @@ export const convertToApiParams = (
   formData.forEach((value, key) => {
     if (typeof value === "string") body[key] = value;
   });
-  return body as unknown as ToolApiParams[ToolEndpoint];
+  return body;
 };
 
 /**
@@ -406,12 +406,6 @@ type ConvertOptionReaders = {
   ) => Partial<ConvertParameters>;
 };
 
-/** The reader shape collapsed for the runtime dispatch, where the endpoint is only a string. */
-type ConvertOptionReader = (
-  body: Record<string, string | undefined>,
-  toExtension: string,
-) => Partial<ConvertParameters>;
-
 // The stored values are strings; these read one back into the typed shape ConvertParameters expects,
 // validating an enum against its allowed set (asEnum) rather than blind-casting an arbitrary string.
 const asFlag = (value: string | undefined): boolean => value === "true";
@@ -583,12 +577,9 @@ export const convertFromApiParams = (
   const fromExtension = body.fromExtension ?? "";
   const toExtension = body.toExtension ?? "";
   const endpoint = convertEndpointFor(fromExtension, toExtension);
-  // Each reader reads only its own endpoint's fields; the runtime endpoint is just a string, so the
-  // precise per-endpoint type is recovered with one widening cast here (every reader accepts a
-  // superset string record).
-  const readOptions = endpoint
-    ? (CONVERT_OPTION_READERS[endpoint] as ConvertOptionReader | undefined)
-    : undefined;
+  // Each reader reads only its own endpoint's fields; the runtime endpoint is just a string, so
+  // readOptions is looked up per-endpoint (undefined when the pair has no reader).
+  const readOptions = endpoint ? CONVERT_OPTION_READERS[endpoint] : undefined;
   return {
     fromExtension,
     toExtension,
diff --git a/frontend/editor/src/core/hooks/tools/shared/toolAutomation.ts b/frontend/editor/src/core/hooks/tools/shared/toolAutomation.ts
index a9368ccdb7..ad9466534c 100644
--- a/frontend/editor/src/core/hooks/tools/shared/toolAutomation.ts
+++ b/frontend/editor/src/core/hooks/tools/shared/toolAutomation.ts
@@ -534,7 +534,7 @@ export function deserializeToolStep(
   const params: ErasedToolParams = {
     ...(config?.defaultParameters ?? {}),
     ...mapped,
-  } as ErasedToolParams;
+  };
   // Validate against the generated endpoint set instead of casting the matched string.
   const operation =
     resolveEndpoint(config, params) ??
diff --git a/frontend/editor/src/core/hooks/tools/shared/toolOperationDescriptor.ts b/frontend/editor/src/core/hooks/tools/shared/toolOperationDescriptor.ts
index 3c8f78d1b8..337909fc7b 100644
--- a/frontend/editor/src/core/hooks/tools/shared/toolOperationDescriptor.ts
+++ b/frontend/editor/src/core/hooks/tools/shared/toolOperationDescriptor.ts
@@ -50,10 +50,9 @@ export function describeToolOperation<
     // A dynamic tool's mapper is typed against the union; narrow to this endpoint (sound - the
     // runtime mapper produces this endpoint's model).
     toApi: (params) => toApiParams(params) as ToolApiParams[E],
-    fromApi: (api) =>
-      ({
-        ...defaultParameters,
-        ...fromApiParams(api as ToolApiParams[CE]),
-      }) as TParams,
+    fromApi: (api) => ({
+      ...defaultParameters,
+      ...fromApiParams(api),
+    }),
   };
 }
diff --git a/frontend/editor/src/core/hooks/tools/shared/toolOperationTypes.ts b/frontend/editor/src/core/hooks/tools/shared/toolOperationTypes.ts
index d01d897002..6cbe97428b 100644
--- a/frontend/editor/src/core/hooks/tools/shared/toolOperationTypes.ts
+++ b/frontend/editor/src/core/hooks/tools/shared/toolOperationTypes.ts
@@ -284,7 +284,7 @@ export function defineSingleFileTool<
   return {
     ...config,
     toolType: ToolType.singleFile,
-  } as SingleFileToolOperationConfig<TParams, TEndpoint>;
+  };
 }
 
 /** Multi-file counterpart of {@link defineSingleFileTool}. */
@@ -300,7 +300,7 @@ export function defineMultiFileTool<
   return {
     ...config,
     toolType: ToolType.multiFile,
-  } as MultiFileToolOperationConfig<TParams, TEndpoint>;
+  };
 }
 
 /**
diff --git a/frontend/editor/src/core/hooks/tools/shared/useToolOperation.ts b/frontend/editor/src/core/hooks/tools/shared/useToolOperation.ts
index 822d281c57..d0ad5f8521 100644
--- a/frontend/editor/src/core/hooks/tools/shared/useToolOperation.ts
+++ b/frontend/editor/src/core/hooks/tools/shared/useToolOperation.ts
@@ -227,10 +227,7 @@ export const useToolOperation = <TParams>(
             : [];
         }
       };
-      window.addEventListener(
-        FILE_EVENTS.markError,
-        errorListener as EventListener,
-      );
+      window.addEventListener(FILE_EVENTS.markError, errorListener);
 
       try {
         let processedFiles: File[];
@@ -619,10 +616,7 @@ export const useToolOperation = <TParams>(
         actions.setError(errorMessage);
         actions.setStatus("");
       } finally {
-        window.removeEventListener(
-          FILE_EVENTS.markError,
-          errorListener as EventListener,
-        );
+        window.removeEventListener(FILE_EVENTS.markError, errorListener);
         actions.setLoading(false);
         actions.setProgress(null);
       }
diff --git a/frontend/editor/src/core/hooks/tools/useFavoriteToolItems.ts b/frontend/editor/src/core/hooks/tools/useFavoriteToolItems.ts
index b1295110db..20a091bcea 100644
--- a/frontend/editor/src/core/hooks/tools/useFavoriteToolItems.ts
+++ b/frontend/editor/src/core/hooks/tools/useFavoriteToolItems.ts
@@ -9,8 +9,8 @@ export function useFavoriteToolItems(
   return useMemo(() => {
     return favoriteTools
       .map((toolId) => {
-        const tool = toolRegistry[toolId as ToolId];
-        return tool ? { id: toolId as ToolId, tool } : null;
+        const tool = toolRegistry[toolId];
+        return tool ? { id: toolId, tool } : null;
       })
       .filter((x): x is { id: ToolId; tool: ToolRegistryEntry } => x !== null)
       .filter(
diff --git a/frontend/editor/src/core/hooks/tools/validateSignature/utils/signatureStatus.test.ts b/frontend/editor/src/core/hooks/tools/validateSignature/utils/signatureStatus.test.ts
index e7fca7622a..e1c621686e 100644
--- a/frontend/editor/src/core/hooks/tools/validateSignature/utils/signatureStatus.test.ts
+++ b/frontend/editor/src/core/hooks/tools/validateSignature/utils/signatureStatus.test.ts
@@ -95,10 +95,7 @@ describe("computeSignatureStatus - trust surfacing", () => {
   });
 
   test("backend error message -> Invalid", () => {
-    const status = computeSignatureStatus(
-      sig({ errorMessage: "boom" } as Partial<SignatureValidationSignature>),
-      t,
-    );
+    const status = computeSignatureStatus(sig({ errorMessage: "boom" }), t);
     expect(status.kind).toBe("invalid");
     expect(status.details).toContain("boom");
   });
diff --git a/frontend/editor/src/core/i18n.ts b/frontend/editor/src/core/i18n.ts
index 839652658c..e69488c4e5 100644
--- a/frontend/editor/src/core/i18n.ts
+++ b/frontend/editor/src/core/i18n.ts
@@ -102,7 +102,7 @@ function getCurrentSourcePriority(): LanguageSource {
   const sourceStr = localStorage.getItem(I18N_STORAGE_KEYS.LANGUAGE_SOURCE);
   const sourceNum = sourceStr ? parseInt(sourceStr, 10) : null;
   return sourceNum !== null && !isNaN(sourceNum)
-    ? (sourceNum as LanguageSource)
+    ? sourceNum
     : LanguageSource.Fallback;
 }
 
diff --git a/frontend/editor/src/core/setupTests.ts b/frontend/editor/src/core/setupTests.ts
index d01c3cb589..a0a347a660 100644
--- a/frontend/editor/src/core/setupTests.ts
+++ b/frontend/editor/src/core/setupTests.ts
@@ -118,7 +118,7 @@ Object.defineProperty(globalThis, "crypto", {
       }
       return array;
     }),
-  } as unknown as Crypto,
+  },
   writable: true,
   configurable: true,
 });
diff --git a/frontend/editor/src/core/tests/stubbed/settings.spec.ts b/frontend/editor/src/core/tests/stubbed/settings.spec.ts
index a9b0bbaa17..1b0bfd3be7 100644
--- a/frontend/editor/src/core/tests/stubbed/settings.spec.ts
+++ b/frontend/editor/src/core/tests/stubbed/settings.spec.ts
@@ -144,15 +144,11 @@ test.describe("Settings dialog", () => {
       const origReplace = window.history.replaceState.bind(window.history);
       window.history.pushState = function (...args) {
         w.__historyOps.push++;
-        return origPush(
-          ...(args as Parameters<typeof window.history.pushState>),
-        );
+        return origPush(...args);
       };
       window.history.replaceState = function (...args) {
         w.__historyOps.replace++;
-        return origReplace(
-          ...(args as Parameters<typeof window.history.replaceState>),
-        );
+        return origReplace(...args);
       };
     });
 
diff --git a/frontend/editor/src/core/tools/Compare.tsx b/frontend/editor/src/core/tools/Compare.tsx
index 0b2a8d5171..6242e12dab 100644
--- a/frontend/editor/src/core/tools/Compare.tsx
+++ b/frontend/editor/src/core/tools/Compare.tsx
@@ -175,8 +175,8 @@ const Compare = (props: BaseToolProps) => {
   );
 
   useEffect(() => {
-    const baseFileId = params.baseFileId as FileId | null;
-    const comparisonFileId = params.comparisonFileId as FileId | null;
+    const baseFileId = params.baseFileId;
+    const comparisonFileId = params.comparisonFileId;
 
     if (!baseFileId || !comparisonFileId) {
       lastProcessedAtRef.current = null;
@@ -437,9 +437,7 @@ const Compare = (props: BaseToolProps) => {
                       : "Select the edited PDF",
                   )
             }
-            excludeIds={
-              otherSlot ? [otherSlot.stirlingFile.fileId as string] : []
-            }
+            excludeIds={otherSlot ? [otherSlot.stirlingFile.fileId] : []}
             disabled={isDisabled}
             onSelect={(result: FileSelectorResult) => {
               if (role === "base") setBaseSlot(result);
diff --git a/frontend/editor/src/core/tools/SharedSign.tsx b/frontend/editor/src/core/tools/SharedSign.tsx
index 5131db40c3..3a335f392a 100644
--- a/frontend/editor/src/core/tools/SharedSign.tsx
+++ b/frontend/editor/src/core/tools/SharedSign.tsx
@@ -129,9 +129,9 @@ const SharedSign = (_props: BaseToolProps) => {
 
   const onItemClick = (item: SessionItem) => {
     if (item.itemType === "signRequest") {
-      void controller.openSignRequest(item as SignRequestSummary);
+      void controller.openSignRequest(item);
     } else {
-      void controller.openSession(item as SessionSummary);
+      void controller.openSession(item);
     }
   };
 
@@ -247,7 +247,7 @@ const SharedSign = (_props: BaseToolProps) => {
       <SegmentedControl
         fullWidth
         value={tab}
-        onChange={(value) => changeTab(value as Tab)}
+        onChange={(value) => changeTab(value)}
         options={[
           { label: t("sharedSign.tab.active", "Active"), value: "active" },
           {
diff --git a/frontend/editor/src/core/tools/annotate/AnnotationPanel.tsx b/frontend/editor/src/core/tools/annotate/AnnotationPanel.tsx
index 6986f4d7e4..0535af1519 100644
--- a/frontend/editor/src/core/tools/annotate/AnnotationPanel.tsx
+++ b/frontend/editor/src/core/tools/annotate/AnnotationPanel.tsx
@@ -891,7 +891,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           ) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 opacity: opacity / 100,
               },
@@ -906,7 +906,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id && selectedAnn.object?.type === 10) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 opacity: opacity / 100,
               },
@@ -921,7 +921,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id && selectedAnn.object?.type === 12) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 opacity: opacity / 100,
               },
@@ -936,7 +936,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id && selectedAnn.object?.type === 11) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 opacity: opacity / 100,
               },
@@ -1017,7 +1017,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 color,
               },
@@ -1032,7 +1032,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 color,
               },
@@ -1047,7 +1047,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 color,
               },
@@ -1140,7 +1140,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 strokeColor: color,
                 color: selectedAnn.object?.color ?? shapeFillColor,
@@ -1163,7 +1163,7 @@ export function AnnotationPanel(props: AnnotationPanelProps) {
           if (selectedAnn?.object?.id) {
             annotationApiRef?.current?.updateAnnotation?.(
               selectedAnn.object.pageIndex ?? 0,
-              selectedAnn.object.id as string,
+              selectedAnn.object.id,
               {
                 color,
                 strokeColor:
diff --git a/frontend/editor/src/core/tools/formFill/FormFieldOverlay.tsx b/frontend/editor/src/core/tools/formFill/FormFieldOverlay.tsx
index 331180ad6f..40f9cdf603 100644
--- a/frontend/editor/src/core/tools/formFill/FormFieldOverlay.tsx
+++ b/frontend/editor/src/core/tools/formFill/FormFieldOverlay.tsx
@@ -146,7 +146,7 @@ function executePdfJs(
     change: "",
     rc: true,
     willCommit: false,
-    target: null as null,
+    target: null,
   };
 
   try {
diff --git a/frontend/editor/src/core/tools/formFill/FormFillContext.tsx b/frontend/editor/src/core/tools/formFill/FormFillContext.tsx
index 97fde82901..8bccb51400 100644
--- a/frontend/editor/src/core/tools/formFill/FormFillContext.tsx
+++ b/frontend/editor/src/core/tools/formFill/FormFillContext.tsx
@@ -377,7 +377,7 @@ export function FormFillProvider({
   const [providerMode, setProviderModeState] = useState<"pdflib" | "pdfbox">(
     initialMode,
   );
-  const providerModeRef = useRef(initialMode as "pdflib" | "pdfbox");
+  const providerModeRef = useRef(initialMode);
   providerModeRef.current = providerMode;
   const provider =
     providerProp ??
diff --git a/frontend/editor/src/core/tools/formFill/providers/PdfiumFormProvider.ts b/frontend/editor/src/core/tools/formFill/providers/PdfiumFormProvider.ts
index 27dc19595a..87d18c3f2f 100644
--- a/frontend/editor/src/core/tools/formFill/providers/PdfiumFormProvider.ts
+++ b/frontend/editor/src/core/tools/formFill/providers/PdfiumFormProvider.ts
@@ -22,12 +22,7 @@ import type {
   ButtonAction,
 } from "@app/tools/formFill/types";
 import type { IFormDataProvider } from "@app/tools/formFill/providers/types";
-import type {
-  PDFDict,
-  PDFString,
-  PDFHexString,
-  PDFName,
-} from "@cantoo/pdf-lib";
+import type { PDFDict } from "@cantoo/pdf-lib";
 
 interface PDFAcroField {
   dict: PDFDict;
@@ -317,7 +312,7 @@ export class PdfiumFormProvider implements IFormDataProvider {
 
       const decodeText = (obj: unknown): string => {
         if (obj instanceof PDFString || obj instanceof PDFHexString)
-          return (obj as PDFString | PDFHexString).decodeText();
+          return obj.decodeText();
         return String(obj ?? "");
       };
 
@@ -410,28 +405,27 @@ export class PdfiumFormProvider implements IFormDataProvider {
 
       const decodeText = (obj: unknown): string | null => {
         if (obj instanceof PDFString || obj instanceof PDFHexString)
-          return (obj as PDFString | PDFHexString).decodeText();
+          return obj.decodeText();
         if (obj instanceof PDFName)
-          return (obj as PDFName).asString() ?? String(obj).replace(/^\//, "");
+          return obj.asString() ?? String(obj).replace(/^\//, "");
         return null;
       };
 
       const parseActionDict = (aObj: unknown): ButtonAction | null => {
         if (!(aObj instanceof PDFDict)) return null;
         // @cantoo/pdf-lib ships without individual .d.ts files so instanceof can't narrow `unknown`
-        const a = aObj as PDFDict;
+        const a = aObj;
         const sObj = a.lookup(PDFName.of("S"));
         if (!(sObj instanceof PDFName)) return null;
         const actionType: string =
-          (sObj as PDFName).asString() ?? String(sObj).replace(/^\//, "");
+          sObj.asString() ?? String(sObj).replace(/^\//, "");
 
         switch (actionType) {
           case "Named": {
             const nObj = a.lookup(PDFName.of("N"));
             const name =
               nObj instanceof PDFName
-                ? ((nObj as PDFName).asString() ??
-                  String(nObj).replace(/^\//, ""))
+                ? (nObj.asString() ?? String(nObj).replace(/^\//, ""))
                 : "";
             return { type: "named", namedAction: name };
           }
diff --git a/frontend/editor/src/core/ui/Checkbox.tsx b/frontend/editor/src/core/ui/Checkbox.tsx
index 778bd13b01..eb7a6263b7 100644
--- a/frontend/editor/src/core/ui/Checkbox.tsx
+++ b/frontend/editor/src/core/ui/Checkbox.tsx
@@ -33,9 +33,7 @@ export const Checkbox = forwardRef<HTMLInputElement, CheckboxProps>(
         <input
           ref={(el) => {
             if (typeof ref === "function") ref(el);
-            else if (ref)
-              (ref as React.MutableRefObject<HTMLInputElement | null>).current =
-                el;
+            else if (ref) ref.current = el;
             if (el) el.indeterminate = !!indeterminate;
           }}
           type="checkbox"
diff --git a/frontend/editor/src/core/utils/bulkselection/parseSelection.ts b/frontend/editor/src/core/utils/bulkselection/parseSelection.ts
index 1705056055..ed8b356651 100644
--- a/frontend/editor/src/core/utils/bulkselection/parseSelection.ts
+++ b/frontend/editor/src/core/utils/bulkselection/parseSelection.ts
@@ -107,7 +107,7 @@ function parseCsvFallback(input: string, max: number): Set<number> {
 }
 
 function clampToRange(v: number, min: number, max: number): number {
-  if (!Number.isFinite(v)) return NaN as unknown as number;
+  if (!Number.isFinite(v)) return NaN;
   return Math.min(Math.max(v, min), max);
 }
 
@@ -281,7 +281,7 @@ class ExpressionParser {
     if (!word) return null;
     const lower = word.toLowerCase();
     if (lower === "even" || lower === "odd") {
-      return lower as "even" | "odd";
+      return lower;
     }
     // Not a keyword; rewind
     this.idx = start;
diff --git a/frontend/editor/src/desktop/hooks/useEndpointConfig.ts b/frontend/editor/src/desktop/hooks/useEndpointConfig.ts
index 9a80435095..490a793df0 100644
--- a/frontend/editor/src/desktop/hooks/useEndpointConfig.ts
+++ b/frontend/editor/src/desktop/hooks/useEndpointConfig.ts
@@ -371,7 +371,10 @@ export function useMultipleEndpointsEnabled(endpoints: string[]): {
         }
       } else {
         setError(message);
-        const fallbackStatus = endpoints.reduce(
+        const fallbackStatus = endpoints.reduce<{
+          status: Record<string, boolean>;
+          details: Record<string, EndpointAvailabilityDetails>;
+        }>(
           (acc, endpointName) => {
             const fallbackDetail: EndpointAvailabilityDetails = {
               enabled: false,
@@ -382,8 +385,8 @@ export function useMultipleEndpointsEnabled(endpoints: string[]): {
             return acc;
           },
           {
-            status: {} as Record<string, boolean>,
-            details: {} as Record<string, EndpointAvailabilityDetails>,
+            status: {},
+            details: {},
           },
         );
 
diff --git a/frontend/editor/src/portal/auth/saasSupabase.ts b/frontend/editor/src/portal/auth/saasSupabase.ts
index ff3ad71b8b..1005d63a63 100644
--- a/frontend/editor/src/portal/auth/saasSupabase.ts
+++ b/frontend/editor/src/portal/auth/saasSupabase.ts
@@ -38,7 +38,7 @@ let configured = false;
 export function ensureSaasSupabase() {
   if (!isSaasSupabaseConfigured) return null;
   if (!configured) {
-    configureSupabase({ url: url as string, key: key as string });
+    configureSupabase({ url: url, key: key });
     configured = true;
   }
   return getSupabaseClient();
diff --git a/frontend/editor/src/portal/components/docs/EndpointReferenceSection.tsx b/frontend/editor/src/portal/components/docs/EndpointReferenceSection.tsx
index 55b1c47f51..0a54de7658 100644
--- a/frontend/editor/src/portal/components/docs/EndpointReferenceSection.tsx
+++ b/frontend/editor/src/portal/components/docs/EndpointReferenceSection.tsx
@@ -1,6 +1,6 @@
 import { useMemo, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { MethodBadge, Tabs, type HttpMethod, type TabItem } from "@app/ui";
+import { MethodBadge, Tabs, type TabItem } from "@app/ui";
 import { VERTICALS, ALL_ENDPOINTS } from "@portal/data/endpoints";
 import { DocsSection } from "@portal/components/docs/DocsSection";
 import "@portal/theme/surface.css";
@@ -61,7 +61,7 @@ export function EndpointReferenceSection() {
             </div>
             {v.endpoints.map((e) => (
               <div key={e.endpoint} className="portal-docs__endpoint-row">
-                <MethodBadge method={"POST" as HttpMethod} />
+                <MethodBadge method={"POST"} />
                 <code className="portal-docs__endpoint-path">{e.endpoint}</code>
                 <span className="portal-docs__endpoint-name">{e.name}</span>
                 <span className="portal-docs__endpoint-fields">
diff --git a/frontend/editor/src/portal/components/pipelines/PipelineStepSettings.test.tsx b/frontend/editor/src/portal/components/pipelines/PipelineStepSettings.test.tsx
index 0b15b7233a..0850499a99 100644
--- a/frontend/editor/src/portal/components/pipelines/PipelineStepSettings.test.tsx
+++ b/frontend/editor/src/portal/components/pipelines/PipelineStepSettings.test.tsx
@@ -275,8 +275,7 @@ describe("PipelineStepSettings: every tool's settings render in the portal", ()
       const Settings = entry.automationSettings as ComponentType<
         ToolAutomationSettingsProps<ErasedToolParams>
       >;
-      const params = (entry.operationConfig?.defaultParameters ??
-        {}) as ErasedToolParams;
+      const params = entry.operationConfig?.defaultParameters ?? {};
 
       const caught: { error: Error | null } = { error: null };
       // The sentinel sibling commits only once the lazy Settings actually renders, so we wait for a
diff --git a/frontend/editor/src/portal/components/policies/PolicySetupWizard.tsx b/frontend/editor/src/portal/components/policies/PolicySetupWizard.tsx
index b50e2efe12..cccdb36e40 100644
--- a/frontend/editor/src/portal/components/policies/PolicySetupWizard.tsx
+++ b/frontend/editor/src/portal/components/policies/PolicySetupWizard.tsx
@@ -457,7 +457,7 @@ function PolicySetupWizardBody({
         variant="underline"
         ariaLabel={t("portal.policies.wizard.tabs.ariaLabel")}
         activeKey={step}
-        onChange={(k) => setStep(k as Step)}
+        onChange={(k) => setStep(k)}
         items={[
           { key: "workflow", label: t("portal.policies.wizard.tabs.workflow") },
           { key: "settings", label: t("portal.policies.wizard.tabs.settings") },
diff --git a/frontend/editor/src/portal/components/processor-flow/useFlowParticles.ts b/frontend/editor/src/portal/components/processor-flow/useFlowParticles.ts
index 65fc6cc9ad..a32ea76a4d 100644
--- a/frontend/editor/src/portal/components/processor-flow/useFlowParticles.ts
+++ b/frontend/editor/src/portal/components/processor-flow/useFlowParticles.ts
@@ -134,10 +134,7 @@ export function useFlowParticles({
         for (let i = 0; i < meanInterval.length; i++) {
           if (!Number.isFinite(meanInterval[i]) || !g.srcs[i]) continue;
           if (now >= nextEmit[i] && particles.length < MAX_PARTICLES) {
-            const c = document.createElementNS(
-              NS,
-              "circle",
-            ) as SVGCircleElement;
+            const c = document.createElementNS(NS, "circle");
             c.setAttribute("r", "2.5");
             c.setAttribute("opacity", "0.75");
             c.style.fill = "var(--c-primary)";
diff --git a/frontend/editor/src/portal/mocks/handlers/policies.ts b/frontend/editor/src/portal/mocks/handlers/policies.ts
index 1bfc435d4c..ce6c041ae9 100644
--- a/frontend/editor/src/portal/mocks/handlers/policies.ts
+++ b/frontend/editor/src/portal/mocks/handlers/policies.ts
@@ -35,7 +35,7 @@ function nextId(categoryId: string): string {
 }
 
 function categoryId(wire: WirePolicy): string {
-  return (wire.output?.options?.categoryId as string | undefined) ?? "";
+  return wire.output?.options?.categoryId ?? "";
 }
 
 export const policiesHandlers = [
diff --git a/frontend/editor/src/portal/mocks/handlers/procurementSaas.ts b/frontend/editor/src/portal/mocks/handlers/procurementSaas.ts
index fe75827c2d..2f5246ce8d 100644
--- a/frontend/editor/src/portal/mocks/handlers/procurementSaas.ts
+++ b/frontend/editor/src/portal/mocks/handlers/procurementSaas.ts
@@ -256,7 +256,7 @@ export const procurementSaasHandlers = [
       stage: "quote",
       licensed: true,
       latestQuote: quote,
-    } as never;
+    };
     return HttpResponse.json(quote);
   }),
   http.post(`${SAAS}/api/v1/procurement/trial/extend`, () => {
diff --git a/frontend/editor/src/portal/queries/adapters.ts b/frontend/editor/src/portal/queries/adapters.ts
index 083e396bad..3cb091d8cd 100644
--- a/frontend/editor/src/portal/queries/adapters.ts
+++ b/frontend/editor/src/portal/queries/adapters.ts
@@ -11,6 +11,6 @@ export function toAsyncState<T>(query: UseQueryResult<T>): AsyncState<T> {
   return {
     data: query.data ?? null,
     loading: query.isPending,
-    error: (query.error as Error | null) ?? null,
+    error: query.error ?? null,
   };
 }
diff --git a/frontend/editor/src/portal/setupTests.ts b/frontend/editor/src/portal/setupTests.ts
index 7de4f9f309..22d95aa1ab 100644
--- a/frontend/editor/src/portal/setupTests.ts
+++ b/frontend/editor/src/portal/setupTests.ts
@@ -50,7 +50,7 @@ global.IntersectionObserver = vi.fn().mockImplementation(() => ({
   observe: vi.fn(),
   unobserve: vi.fn(),
   disconnect: vi.fn(),
-})) as unknown as typeof IntersectionObserver;
+}));
 
 Object.defineProperty(window, "matchMedia", {
   writable: true,
diff --git a/frontend/editor/src/proprietary/auth/springAuthClient.test.ts b/frontend/editor/src/proprietary/auth/springAuthClient.test.ts
index 54fed2028d..13f5c6d651 100644
--- a/frontend/editor/src/proprietary/auth/springAuthClient.test.ts
+++ b/frontend/editor/src/proprietary/auth/springAuthClient.test.ts
@@ -12,11 +12,7 @@ import apiClient from "@app/services/apiClient";
 // + oauthNavigation seam, so springAuth routes through the mocks below.
 import "@app/auth/configureSpringAuth";
 import { allowConsole, expectConsole } from "@app/tests/failOnConsole";
-import {
-  AxiosError,
-  type AxiosResponse,
-  type InternalAxiosRequestConfig,
-} from "axios";
+import { AxiosError, type InternalAxiosRequestConfig } from "axios";
 
 // Mock apiClient
 vi.mock("@app/services/apiClient");
@@ -59,7 +55,7 @@ describe("SpringAuthClient", () => {
       vi.mocked(apiClient.get).mockResolvedValueOnce({
         status: 200,
         data: { user: mockUser },
-      } as unknown as AxiosResponse);
+      });
 
       const result = await springAuth.getSession();
 
@@ -176,7 +172,7 @@ describe("SpringAuthClient", () => {
             expires_in: 3600,
           },
         },
-      } as unknown as AxiosResponse);
+      });
 
       // Spy on window.dispatchEvent
       const dispatchEventSpy = vi.spyOn(window, "dispatchEvent");
@@ -235,7 +231,7 @@ describe("SpringAuthClient", () => {
       vi.mocked(apiClient.post).mockResolvedValueOnce({
         status: 200,
         data: {},
-      } as unknown as AxiosResponse);
+      });
 
       const result = await springAuth.signOut();
 
@@ -288,7 +284,7 @@ describe("SpringAuthClient", () => {
             expires_in: 3600,
           },
         },
-      } as unknown as AxiosResponse);
+      });
 
       const result = await springAuth.refreshSession();
 
@@ -375,7 +371,7 @@ describe("SpringAuthClient", () => {
         expect(isSafePostLoginRedirect("")).toBe(false);
         expect(isSafePostLoginRedirect(null)).toBe(false);
         expect(isSafePostLoginRedirect(undefined)).toBe(false);
-        expect(isSafePostLoginRedirect(42 as unknown)).toBe(false);
+        expect(isSafePostLoginRedirect(42)).toBe(false);
       });
 
       it("rejects protocol-relative and absolute URLs (open-redirect guard)", () => {
diff --git a/frontend/editor/src/proprietary/auth/supabase/UseSession.tsx b/frontend/editor/src/proprietary/auth/supabase/UseSession.tsx
index 6bcc6b501e..385f3f4e35 100644
--- a/frontend/editor/src/proprietary/auth/supabase/UseSession.tsx
+++ b/frontend/editor/src/proprietary/auth/supabase/UseSession.tsx
@@ -46,7 +46,7 @@ function mapUser(user: SbUser): AuthUser {
       "",
     role: readRole(user),
     is_anonymous: user.is_anonymous,
-    app_metadata: user.app_metadata as Record<string, unknown>,
+    app_metadata: user.app_metadata,
   };
 }
 
diff --git a/frontend/editor/src/proprietary/components/policies/policyRunSettles.test.ts b/frontend/editor/src/proprietary/components/policies/policyRunSettles.test.ts
index fdce331821..c3c6be7137 100644
--- a/frontend/editor/src/proprietary/components/policies/policyRunSettles.test.ts
+++ b/frontend/editor/src/proprietary/components/policies/policyRunSettles.test.ts
@@ -7,20 +7,19 @@ import type { PolicyRunRecord } from "@app/components/policies/policyRunStore";
  * effect used to skip those runs entirely, so `imported` never flipped and the
  * file's badge + blocking overlay spun forever - on every engine.
  */
-const run = (overrides: Partial<PolicyRunRecord> = {}): PolicyRunRecord =>
-  ({
-    runId: "r",
-    categoryId: "security",
-    fileId: "f",
-    fileName: "f.pdf",
-    fileSize: 1,
-    target: "saas",
-    status: "COMPLETED",
-    outputs: [],
-    error: null,
-    startedAt: 0,
-    ...overrides,
-  }) as PolicyRunRecord;
+const run = (overrides: Partial<PolicyRunRecord> = {}): PolicyRunRecord => ({
+  runId: "r",
+  categoryId: "security",
+  fileId: "f",
+  fileName: "f.pdf",
+  fileSize: 1,
+  target: "saas",
+  status: "COMPLETED",
+  outputs: [],
+  error: null,
+  startedAt: 0,
+  ...overrides,
+});
 
 describe("finishedWithNothingToDeliver", () => {
   it("settles a completed run that produced no output", () => {
diff --git a/frontend/editor/src/proprietary/components/policies/useClientSideClassification.ts b/frontend/editor/src/proprietary/components/policies/useClientSideClassification.ts
index 64fd849d87..ede1768b2a 100644
--- a/frontend/editor/src/proprietary/components/policies/useClientSideClassification.ts
+++ b/frontend/editor/src/proprietary/components/policies/useClientSideClassification.ts
@@ -99,7 +99,7 @@ export function useClientSideClassification(): void {
           if (claimed.current.has(key)) continue;
           claimed.current.add(key);
           const verdict = await classifyStub(
-            stub.id as FileId,
+            stub.id,
             stub.name,
             stub.size ?? 0,
           );
@@ -108,11 +108,11 @@ export function useClientSideClassification(): void {
           if (verdict == null) continue;
           // Deliver unconditionally - a re-render must never discard a computed
           // (and already metered) result. Writes are idempotent.
-          updateStirlingFileStub(stub.id as FileId, {
+          updateStirlingFileStub(stub.id, {
             classificationLabels: verdict.labels,
             classificationConfidence: verdict.confidence,
           });
-          const ok = await fileStorage.updateFileMetadata(stub.id as FileId, {
+          const ok = await fileStorage.updateFileMetadata(stub.id, {
             classificationLabels: verdict.labels,
             classificationConfidence: verdict.confidence,
           });
diff --git a/frontend/editor/src/proprietary/components/policies/usePolicyAutoRun.ts b/frontend/editor/src/proprietary/components/policies/usePolicyAutoRun.ts
index 936fef8119..0638b1432c 100644
--- a/frontend/editor/src/proprietary/components/policies/usePolicyAutoRun.ts
+++ b/frontend/editor/src/proprietary/components/policies/usePolicyAutoRun.ts
@@ -768,7 +768,7 @@ async function importOutputs(
     // Mark the outputs handled BEFORE adding them (belt-and-suspenders session
     // guard on top of derivedFromTool) so the auto-run never enforces the policy
     // on its own output — that would version endlessly in a loop.
-    for (const s of categorized) markHandled(s.id as string);
+    for (const s of categorized) markHandled(s.id);
     deliveredIds = categorized.map((s) => s.id as string);
     if (ctx.parentStub) {
       // Input is in the active workspace: version it in place, silently — the
@@ -799,7 +799,7 @@ async function importOutputs(
       derivedFromTool: true,
     });
     // Belt-and-suspenders session guard on top of derivedFromTool.
-    for (const f of added) markHandled(f.fileId as string);
+    for (const f of added) markHandled(f.fileId);
     deliveredIds = added.map((f) => f.fileId as string);
     // Mark each new-file output as tool-derived (the versioned path gets this from the
     // CONSUME_FILES reducer; the addFiles path doesn't). This is the real loop guard: the dispatch
diff --git a/frontend/editor/src/proprietary/components/shared/FileSidebarGroupControls.tsx b/frontend/editor/src/proprietary/components/shared/FileSidebarGroupControls.tsx
index 41d1358594..1b37a13bb7 100644
--- a/frontend/editor/src/proprietary/components/shared/FileSidebarGroupControls.tsx
+++ b/frontend/editor/src/proprietary/components/shared/FileSidebarGroupControls.tsx
@@ -46,7 +46,7 @@ export function FileSidebarGroupControls({
       const ids = new Set<string>();
       for (const key of category.labelKeys) {
         for (const stub of byLabel.get(key)?.stubs ?? []) {
-          ids.add(stub.id as string);
+          ids.add(stub.id);
         }
       }
       counts.set(category.id, ids.size);
diff --git a/frontend/editor/src/proprietary/components/shared/InviteMembersModal.tsx b/frontend/editor/src/proprietary/components/shared/InviteMembersModal.tsx
index e57f60395f..063fb1c4ef 100644
--- a/frontend/editor/src/proprietary/components/shared/InviteMembersModal.tsx
+++ b/frontend/editor/src/proprietary/components/shared/InviteMembersModal.tsx
@@ -460,7 +460,7 @@ export default function InviteMembersModal({
               <SegmentedControl
                 value={inviteMode}
                 onChange={(value) => {
-                  setInviteMode(value as "email" | "direct" | "link");
+                  setInviteMode(value);
                   setGeneratedInviteLink(null);
                 }}
                 options={[
diff --git a/frontend/editor/src/proprietary/components/shared/UpgradeBanner.tsx b/frontend/editor/src/proprietary/components/shared/UpgradeBanner.tsx
index 365c64a030..fdb92dc271 100644
--- a/frontend/editor/src/proprietary/components/shared/UpgradeBanner.tsx
+++ b/frontend/editor/src/proprietary/components/shared/UpgradeBanner.tsx
@@ -67,15 +67,9 @@ const UpgradeBanner: React.FC = () => {
       }
     };
 
-    window.addEventListener(
-      UPGRADE_BANNER_TEST_EVENT,
-      handleTestEvent as EventListener,
-    );
+    window.addEventListener(UPGRADE_BANNER_TEST_EVENT, handleTestEvent);
     return () => {
-      window.removeEventListener(
-        UPGRADE_BANNER_TEST_EVENT,
-        handleTestEvent as EventListener,
-      );
+      window.removeEventListener(UPGRADE_BANNER_TEST_EVENT, handleTestEvent);
     };
   }, [isDev]);
 
diff --git a/frontend/editor/src/proprietary/components/shared/config/LoginLandingSetting.test.tsx b/frontend/editor/src/proprietary/components/shared/config/LoginLandingSetting.test.tsx
index 31d45c0d45..b9caf6ba8d 100644
--- a/frontend/editor/src/proprietary/components/shared/config/LoginLandingSetting.test.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/LoginLandingSetting.test.tsx
@@ -3,7 +3,7 @@ import { render, screen, waitFor } from "@testing-library/react";
 import { MantineProvider } from "@mantine/core";
 
 const h = vi.hoisted(() => ({
-  prefs: { loginLandingView: "processor" as "processor" | "editor" },
+  prefs: { loginLandingView: "processor" },
   update: vi.fn(),
   get: vi.fn(),
 }));
diff --git a/frontend/editor/src/proprietary/components/shared/config/configSections/AdminConnectionsSection.tsx b/frontend/editor/src/proprietary/components/shared/config/configSections/AdminConnectionsSection.tsx
index f788551551..b993889e52 100644
--- a/frontend/editor/src/proprietary/components/shared/config/configSections/AdminConnectionsSection.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/configSections/AdminConnectionsSection.tsx
@@ -518,11 +518,11 @@ export default function AdminConnectionsSection() {
     updatedSettings: Record<string, unknown>,
   ) => {
     if (provider.id === "smtp") {
-      setSettings({ ...settings, mail: updatedSettings as MailSettings });
+      setSettings({ ...settings, mail: updatedSettings });
     } else if (provider.id === "telegram") {
       setSettings({
         ...settings,
-        telegram: updatedSettings as TelegramSettingsData,
+        telegram: updatedSettings,
       });
     } else if (provider.id === "googledrive") {
       const gd = updatedSettings as GoogleDriveSettings;
@@ -534,7 +534,7 @@ export default function AdminConnectionsSection() {
         googleDriveAppId: gd.appId,
       });
     } else if (provider.id === "saml2") {
-      setSettings({ ...settings, saml2: updatedSettings as Saml2Settings });
+      setSettings({ ...settings, saml2: updatedSettings });
     } else if (provider.id === "oauth2-generic") {
       const generic = updatedSettings as OAuth2GenericSettings;
       setSettings({ ...settings, oauth2: { ...settings.oauth2, ...generic } });
diff --git a/frontend/editor/src/proprietary/components/shared/config/configSections/AdminUsageSection.tsx b/frontend/editor/src/proprietary/components/shared/config/configSections/AdminUsageSection.tsx
index 6b46789bdd..d0a0a1b2e9 100644
--- a/frontend/editor/src/proprietary/components/shared/config/configSections/AdminUsageSection.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/configSections/AdminUsageSection.tsx
@@ -332,9 +332,7 @@ const AdminUsageSection: React.FC = () => {
             <Group>
               <SegmentedControl
                 value={displayMode}
-                onChange={(value) =>
-                  setDisplayMode(value as "top10" | "top20" | "all")
-                }
+                onChange={(value) => setDisplayMode(value)}
                 options={[
                   {
                     value: "top10",
@@ -373,7 +371,7 @@ const AdminUsageSection: React.FC = () => {
             </Text>
             <SegmentedControl
               value={dataType}
-              onChange={(value) => setDataType(value as "all" | "api" | "ui")}
+              onChange={(value) => setDataType(value)}
               options={[
                 {
                   value: "all",
diff --git a/frontend/editor/src/proprietary/components/shared/config/configSections/audit/AuditEventsTable.tsx b/frontend/editor/src/proprietary/components/shared/config/configSections/audit/AuditEventsTable.tsx
index feca3696d4..22263596c0 100644
--- a/frontend/editor/src/proprietary/components/shared/config/configSections/audit/AuditEventsTable.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/configSections/audit/AuditEventsTable.tsx
@@ -257,11 +257,9 @@ const AuditEventsTable: React.FC<AuditEventsTableProps> = ({
                 verticalSpacing="sm"
                 withRowBorders
                 highlightOnHover
-                style={
-                  {
-                    "--table-border-color": "var(--mantine-color-gray-3)",
-                  } as React.CSSProperties
-                }
+                style={{
+                  "--table-border-color": "var(--mantine-color-gray-3)",
+                }}
               >
                 <Table.Thead>
                   <Table.Tr
diff --git a/frontend/editor/src/proprietary/components/shared/config/configSections/plan/LicenseKeySection.tsx b/frontend/editor/src/proprietary/components/shared/config/configSections/plan/LicenseKeySection.tsx
index 4b890e683a..1b19656b16 100644
--- a/frontend/editor/src/proprietary/components/shared/config/configSections/plan/LicenseKeySection.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/configSections/plan/LicenseKeySection.tsx
@@ -233,7 +233,7 @@ const LicenseKeySection: React.FC<LicenseKeySectionProps> = ({
           <SegmentedControl
             value={inputMethod}
             onChange={(value) => {
-              setInputMethod(value as "text" | "file");
+              setInputMethod(value);
               // Clear opposite input when switching
               if (value === "text") setLicenseFile(null);
               if (value === "file") setLicenseKeyInput("");
diff --git a/frontend/editor/src/proprietary/components/shared/config/configSections/usage/UsageAnalyticsTable.tsx b/frontend/editor/src/proprietary/components/shared/config/configSections/usage/UsageAnalyticsTable.tsx
index f27d5d09a3..a89cb477e3 100644
--- a/frontend/editor/src/proprietary/components/shared/config/configSections/usage/UsageAnalyticsTable.tsx
+++ b/frontend/editor/src/proprietary/components/shared/config/configSections/usage/UsageAnalyticsTable.tsx
@@ -32,11 +32,9 @@ const UsageAnalyticsTable: React.FC<UsageAnalyticsTableProps> = ({ data }) => {
           verticalSpacing="sm"
           withRowBorders
           highlightOnHover
-          style={
-            {
-              "--table-border-color": "var(--mantine-color-gray-3)",
-            } as React.CSSProperties
-          }
+          style={{
+            "--table-border-color": "var(--mantine-color-gray-3)",
+          }}
         >
           <TableThead>
             <TableTr style={{ backgroundColor: "var(--mantine-color-gray-0)" }}>
diff --git a/frontend/editor/src/proprietary/components/shared/fileSidebarGrouping.tsx b/frontend/editor/src/proprietary/components/shared/fileSidebarGrouping.tsx
index baf3d812cb..447bd19a68 100644
--- a/frontend/editor/src/proprietary/components/shared/fileSidebarGrouping.tsx
+++ b/frontend/editor/src/proprietary/components/shared/fileSidebarGrouping.tsx
@@ -20,7 +20,6 @@ import {
 } from "@app/services/fileSidebarCategories";
 import { buildLabelGroups } from "@app/components/shared/fileSidebarGroupingLogic";
 import { scheduleIdle } from "@app/utils/scheduleIdle";
-import type { FileId } from "@app/types/file";
 import type { StirlingFileStub } from "@app/types/fileContext";
 import type { FileSidebarGroup } from "@core/components/shared/fileSidebarGrouping";
 
@@ -81,7 +80,7 @@ export function useFileSidebarGroups(
           if (cancelled) return;
           attempted.current.add(attemptKey(stub));
           if (labels) {
-            const ok = await fileStorage.updateFileMetadata(stub.id as FileId, {
+            const ok = await fileStorage.updateFileMetadata(stub.id, {
               classificationLabels: labels,
             });
             if (ok) wrote = true;
diff --git a/frontend/editor/src/proprietary/components/shared/fileSidebarGroupingLogic.ts b/frontend/editor/src/proprietary/components/shared/fileSidebarGroupingLogic.ts
index 82569a9bd5..5b4b30ce33 100644
--- a/frontend/editor/src/proprietary/components/shared/fileSidebarGroupingLogic.ts
+++ b/frontend/editor/src/proprietary/components/shared/fileSidebarGroupingLogic.ts
@@ -70,7 +70,7 @@ export function buildLabelGroups(
   // Other = files in no visible group: unlabelled, or labelled only under hidden categories.
   const covered = new Set<string>();
   for (const group of visible) {
-    for (const stub of group.stubs) covered.add(stub.id as string);
+    for (const stub of group.stubs) covered.add(stub.id);
   }
   const other = stubs.filter((stub) => !covered.has(stub.id as string));
 
diff --git a/frontend/editor/src/proprietary/hooks/useFolderRunStatuses.ts b/frontend/editor/src/proprietary/hooks/useFolderRunStatuses.ts
index 031d514f5f..78f00b1fab 100644
--- a/frontend/editor/src/proprietary/hooks/useFolderRunStatuses.ts
+++ b/frontend/editor/src/proprietary/hooks/useFolderRunStatuses.ts
@@ -51,7 +51,7 @@ export function useFolderRunStatuses(
             );
             return [folder.id, deriveStatus(runs)] as const;
           } catch {
-            return [folder.id, "idle" as FolderRunStatus] as const;
+            return [folder.id, "idle"] as const;
           }
         }),
       );
diff --git a/frontend/editor/src/proprietary/policies/codec.ts b/frontend/editor/src/proprietary/policies/codec.ts
index 2ef68514e4..e6fbdf739d 100644
--- a/frontend/editor/src/proprietary/policies/codec.ts
+++ b/frontend/editor/src/proprietary/policies/codec.ts
@@ -62,10 +62,8 @@ export function fromWirePolicy(policy: WirePolicy): PolicyDecodedState {
     name: policy.name,
     enabled: policy.enabled,
     categoryId,
-    sources: Array.isArray(raw.sources) ? (raw.sources as string[]) : [],
-    scopeTypes: Array.isArray(raw.scopeTypes)
-      ? (raw.scopeTypes as string[])
-      : [],
+    sources: Array.isArray(raw.sources) ? raw.sources : [],
+    scopeTypes: Array.isArray(raw.scopeTypes) ? raw.scopeTypes : [],
     reviewerEmail: str(raw.reviewerEmail),
     fieldValues: raw.fieldValues ?? {},
     runOn: resolveRunOn(raw.runOn, categoryId),
diff --git a/frontend/editor/src/proprietary/routes/Login.test.tsx b/frontend/editor/src/proprietary/routes/Login.test.tsx
index d2cb80360f..29ae9d9d79 100644
--- a/frontend/editor/src/proprietary/routes/Login.test.tsx
+++ b/frontend/editor/src/proprietary/routes/Login.test.tsx
@@ -10,7 +10,6 @@ import { PreferencesProvider } from "@app/contexts/PreferencesContext";
 import { TestQueryProvider } from "@app/tests/utils/TestQueryProvider";
 import apiClient from "@app/services/apiClient";
 import { configureSpringAuth } from "@app/auth/config";
-import type { AxiosInstance } from "axios";
 
 // Mock i18n to return fallback text
 vi.mock("react-i18next", () => ({
@@ -137,7 +136,7 @@ describe("Login", () => {
     // The shared login hook reads getSpringAuthConfig().http; in the real app,
     // startup points that at apiClient. Mirror that here so the mocked apiClient
     // serves the login-ui-data fetch.
-    configureSpringAuth({ http: apiClient as unknown as AxiosInstance });
+    configureSpringAuth({ http: apiClient });
   });
 
   it("should render login form", async () => {
diff --git a/frontend/editor/src/proprietary/services/heuristic/heuristicEngine.ts b/frontend/editor/src/proprietary/services/heuristic/heuristicEngine.ts
index ed01b9542e..8d2f795636 100644
--- a/frontend/editor/src/proprietary/services/heuristic/heuristicEngine.ts
+++ b/frontend/editor/src/proprietary/services/heuristic/heuristicEngine.ts
@@ -387,8 +387,7 @@ export async function ensureRulesLoaded(): Promise<void> {
   if (!loadPromise) {
     loadPromise = import("@app/services/heuristic/heuristicRules.json").then(
       (mod) => {
-        const root = ((mod as { default?: RulesFile }).default ??
-          (mod as RulesFile)) as RulesFile;
+        const root = (mod as { default?: RulesFile }).default ?? mod;
         PREPARED = prepare(root.labels ?? []);
         PRIORS = loadPriors(root.priors ?? {});
       },
diff --git a/frontend/editor/src/proprietary/services/heuristic/heuristicExtractor.ts b/frontend/editor/src/proprietary/services/heuristic/heuristicExtractor.ts
index 426c1133e1..fb51b407b6 100644
--- a/frontend/editor/src/proprietary/services/heuristic/heuristicExtractor.ts
+++ b/frontend/editor/src/proprietary/services/heuristic/heuristicExtractor.ts
@@ -186,8 +186,7 @@ async function metadata(
   } catch {
     return {};
   }
-  const get = (k: string) =>
-    typeof info[k] === "string" ? (info[k] as string) : "";
+  const get = (k: string) => (typeof info[k] === "string" ? info[k] : "");
   return {
     title: get("Title"),
     author: get("Author"),
diff --git a/frontend/editor/src/proprietary/services/policyExport.ts b/frontend/editor/src/proprietary/services/policyExport.ts
index 78b747182b..91b68f8edd 100644
--- a/frontend/editor/src/proprietary/services/policyExport.ts
+++ b/frontend/editor/src/proprietary/services/policyExport.ts
@@ -222,7 +222,7 @@ export async function enforceExportPolicies(
             fileId,
             fileName: file.name,
             fileSize: file.size,
-            target: versionRun!.target,
+            target: versionRun.target,
             status: "COMPLETED",
             outputs: versionRun.outputs,
             error: null,
diff --git a/frontend/editor/src/saas/auth/UseSession.test.ts b/frontend/editor/src/saas/auth/UseSession.test.ts
index d5f8124948..94e1ffcb6a 100644
--- a/frontend/editor/src/saas/auth/UseSession.test.ts
+++ b/frontend/editor/src/saas/auth/UseSession.test.ts
@@ -17,7 +17,7 @@ function makeUser(overrides: Partial<User> = {}): User {
     user_metadata: {},
     created_at: "2026-01-01T00:00:00Z",
     ...overrides,
-  } as User;
+  };
 }
 
 describe("saas deriveDisplayName", () => {
diff --git a/frontend/editor/src/saas/components/SignupRequiredBootstrap.tsx b/frontend/editor/src/saas/components/SignupRequiredBootstrap.tsx
index b9028ce22b..7ba4230ef5 100644
--- a/frontend/editor/src/saas/components/SignupRequiredBootstrap.tsx
+++ b/frontend/editor/src/saas/components/SignupRequiredBootstrap.tsx
@@ -46,12 +46,8 @@ export default function SignupRequiredBootstrap() {
         return true;
       });
     };
-    window.addEventListener("payg:signupRequired", handler as EventListener);
-    return () =>
-      window.removeEventListener(
-        "payg:signupRequired",
-        handler as EventListener,
-      );
+    window.addEventListener("payg:signupRequired", handler);
+    return () => window.removeEventListener("payg:signupRequired", handler);
   }, []);
 
   // Map the server's gate categories to user-facing nouns. The server
diff --git a/frontend/editor/src/saas/components/shared/AppConfigModal.tsx b/frontend/editor/src/saas/components/shared/AppConfigModal.tsx
index ab93f734fb..11b8957deb 100644
--- a/frontend/editor/src/saas/components/shared/AppConfigModal.tsx
+++ b/frontend/editor/src/saas/components/shared/AppConfigModal.tsx
@@ -80,12 +80,8 @@ const AppConfigModal: React.FC<AppConfigModalProps> = ({
         setMobilePane("content");
       }
     };
-    window.addEventListener("appConfig:navigate", handler as EventListener);
-    return () =>
-      window.removeEventListener(
-        "appConfig:navigate",
-        handler as EventListener,
-      );
+    window.addEventListener("appConfig:navigate", handler);
+    return () => window.removeEventListener("appConfig:navigate", handler);
   }, []);
 
   // When the modal opens via a /settings/<section> deep link (navigateToSettings — e.g. the
@@ -122,9 +118,8 @@ const AppConfigModal: React.FC<AppConfigModalProps> = ({
         setNotice(detail.notice);
       }
     };
-    window.addEventListener("appConfig:notice", handler as EventListener);
-    return () =>
-      window.removeEventListener("appConfig:notice", handler as EventListener);
+    window.addEventListener("appConfig:notice", handler);
+    return () => window.removeEventListener("appConfig:notice", handler);
   }, []);
 
   // Full-screen overlays that live inside our React tree (e.g. the PAYG
@@ -140,9 +135,8 @@ const AppConfigModal: React.FC<AppConfigModalProps> = ({
         | undefined;
       setOverlayActive(Boolean(detail?.open));
     };
-    window.addEventListener("appConfig:overlay", handler as EventListener);
-    return () =>
-      window.removeEventListener("appConfig:overlay", handler as EventListener);
+    window.addEventListener("appConfig:overlay", handler);
+    return () => window.removeEventListener("appConfig:overlay", handler);
   }, []);
 
   const colors = useMemo(
diff --git a/frontend/editor/src/saas/components/shared/charts/StackedBarChart.tsx b/frontend/editor/src/saas/components/shared/charts/StackedBarChart.tsx
index 5f56843dae..0224b0837b 100644
--- a/frontend/editor/src/saas/components/shared/charts/StackedBarChart.tsx
+++ b/frontend/editor/src/saas/components/shared/charts/StackedBarChart.tsx
@@ -211,11 +211,9 @@ export default function StackedBarChart({
           setTooltipContent(html);
           const tooltip = tooltipRef.current;
           if (tooltip) tooltip.style.opacity = "1";
-          positionTooltip(event as unknown as MouseEvent);
+          positionTooltip(event);
         })
-        .on("mousemove", (event: MouseEvent) =>
-          positionTooltip(event as unknown as MouseEvent),
-        )
+        .on("mousemove", (event: MouseEvent) => positionTooltip(event))
         .on("mouseleave", hideTooltip);
 
       // Animate reveal of used segments (only on first load, not on re-renders)
diff --git a/frontend/editor/src/saas/components/shared/config/configSections/Overview.tsx b/frontend/editor/src/saas/components/shared/config/configSections/Overview.tsx
index 3a28152425..62f84977c1 100644
--- a/frontend/editor/src/saas/components/shared/config/configSections/Overview.tsx
+++ b/frontend/editor/src/saas/components/shared/config/configSections/Overview.tsx
@@ -562,15 +562,7 @@ const Overview: React.FC<OverviewProps> = ({ onLogoutClick }) => {
                           style={{ width: 16, height: 16 }}
                         />
                       }
-                      onClick={() =>
-                        handleOAuthUpgrade(
-                          provider.id as
-                            | "github"
-                            | "google"
-                            | "apple"
-                            | "azure",
-                        )
-                      }
+                      onClick={() => handleOAuthUpgrade(provider.id)}
                       disabled={isLoading}
                     >
                       {provider.label}
diff --git a/frontend/editor/src/saas/components/tools/sign/SignSettings.tsx b/frontend/editor/src/saas/components/tools/sign/SignSettings.tsx
index 503087cbe4..59920ab6fb 100644
--- a/frontend/editor/src/saas/components/tools/sign/SignSettings.tsx
+++ b/frontend/editor/src/saas/components/tools/sign/SignSettings.tsx
@@ -547,7 +547,7 @@ const SignSettings = ({
       return;
     }
     const nextSource = allowedSignatureSources.includes(
-      parameters.signatureType as SignatureSource,
+      parameters.signatureType,
     )
       ? (parameters.signatureType as SignatureSource)
       : effectiveDefaultSource;
@@ -1314,9 +1314,7 @@ const SignSettings = ({
           <SegmentedControl
             value={signatureSource}
             fullWidth
-            onChange={(value) =>
-              handleSignatureSourceChange(value as SignatureSource)
-            }
+            onChange={(value) => handleSignatureSourceChange(value)}
             options={sourceOptions}
           />
         )}
diff --git a/frontend/editor/src/saas/routes/OAuthConsent.tsx b/frontend/editor/src/saas/routes/OAuthConsent.tsx
index f22f13fa19..f2acc03899 100644
--- a/frontend/editor/src/saas/routes/OAuthConsent.tsx
+++ b/frontend/editor/src/saas/routes/OAuthConsent.tsx
@@ -35,9 +35,8 @@ interface AuthorizationDetails {
   };
 }
 
-const SUPABASE_URL = import.meta.env.VITE_SUPABASE_URL as string;
-const SUPABASE_KEY = import.meta.env
-  .VITE_SUPABASE_PUBLISHABLE_DEFAULT_KEY as string;
+const SUPABASE_URL = import.meta.env.VITE_SUPABASE_URL;
+const SUPABASE_KEY = import.meta.env.VITE_SUPABASE_PUBLISHABLE_DEFAULT_KEY;
 
 async function gotrue(
   path: string,
diff --git a/frontend/editor/src/saas/setupTests.ts b/frontend/editor/src/saas/setupTests.ts
index 3e8864e49e..6b04e18efd 100644
--- a/frontend/editor/src/saas/setupTests.ts
+++ b/frontend/editor/src/saas/setupTests.ts
@@ -130,7 +130,7 @@ Object.defineProperty(globalThis, "crypto", {
         }
         return array;
       }),
-  } as unknown as Crypto,
+  },
   writable: true,
   configurable: true,
 });