feat(shared): make @shared the single home for brand logo assets (#6714)

## What

Makes `@shared` the single home for the Stirling brand logo assets.
Moves the editor's two logo sets — `classic-logo` + `modern-logo` (22
files: marks, wordmarks, favicons, login headers, PNGs) — out of
`editor/public/` into `shared/assets/brand/`, and adds a Storybook
**Brand/Logos** gallery.

## Why this shape (not a plain move)

The editor serves logos by **URL** from `public/` and switches
`classic`/`modern` by a **user preference** (`useLogoAssets`,
`manifest.json` / `manifest-classic.json`, `index.html` favicon links).
Rewiring all that to module imports would be a large, risky change to
the variant system.

Instead the editor keeps its variant system **unchanged** and just
sources the files from shared: `vite-plugin-static-copy` copies
`shared/assets/brand/{classic,modern}-logo/*` back to the served
`/{classic,modern}-logo` paths (the editor already uses this plugin for
pdfium/pdfjs assets). Single source of truth in shared, zero editor
code/manifest/markup changes.

## Verified

- **Build:** editor builds with both sets present at
`dist/{modern,classic}-logo/`; `manifest.json` + favicon refs resolve.
- **Dev:** the vite dev server serves the bridged paths —
`/modern-logo/logo512.png`,
`/modern-logo/StirlingPDFLogoNoTextDark.svg`,
`/classic-logo/favicon.ico` all return **HTTP 200** (the plugin's dev
middleware).
- Typecheck clean on core/proprietary/saas; prettier clean; `storybook
build` succeeds with the `Brand/Logos` gallery bundled.
- The portal's existing `@shared/assets` brand imports are untouched.

## Follow-ups (not in this PR)

- **Dedup:** `shared/assets/stirling-mark-*.svg` is byte-identical to
`brand/modern-logo/StirlingPDFLogoNoTextDark.svg`, and
`stirling-pdf-logo-*` is a near-twin of the modern wordmark. Reconciling
these (and re-pointing the portal) needs a designer eye on which
wordmark is canonical, so it's left out here to avoid changing the
portal's rendered logo.
- `editor/src/logo.svg` appears unused (no references) — candidate for
deletion separately.

frontend/editor/src/core/hooks/useLogoAssets.test.ts

@@ -10,6 +10,11 @@ import type { LogoVariant } from "@app/services/preferencesService";
  */
 describe("useLogoAssets - Logo Asset Files", () => {
   const publicDir = path.resolve(__dirname, "../../../public");
+  // Brand logo assets live in the shared design system; the editor's vite
+  // config copies shared/assets/brand/<folder>/* into the served root at build
+  // time (see viteStaticCopy in editor/vite.config.ts), so useLogoAssets can
+  // keep referencing them by their public-URL path. Validate them at source.
+  const brandDir = path.resolve(__dirname, "../../../../shared/assets/brand");
 
   // All asset files that useLogoAssets references
   const requiredAssets = [
@@ -27,7 +32,7 @@ describe("useLogoAssets - Logo Asset Files", () => {
 
   describe.each(logoVariants)("%s logo variant", (variant) => {
     const folder = LOGO_FOLDER_BY_VARIANT[variant];
-    const folderPath = path.join(publicDir, folder);
+    const folderPath = path.join(brandDir, folder);
 
     test(`folder "${folder}" should exist`, () => {
       expect(fs.existsSync(folderPath)).toBe(true);

frontend/editor/src/proprietary/routes/Login.tsx

@@ -22,7 +22,7 @@ import {
 import SpringLoginForm from "@shared/auth/ui/SpringLoginForm";
 import { useSpringLogin } from "@shared/auth/ui/useSpringLogin";
 import LoggedInState from "@app/routes/login/LoggedInState";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 export default function Login() {
   const navigate = useNavigate();

frontend/editor/src/proprietary/routes/Signup.tsx

@@ -16,7 +16,7 @@ import {
   SignupFieldErrors,
 } from "@app/routes/signup/SignupFormValidation";
 import { useAuthService } from "@app/routes/signup/AuthService";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 export default function Signup() {
   const navigate = useNavigate();

frontend/editor/src/saas/routes/Login.tsx

@@ -19,7 +19,7 @@ import ErrorMessage from "@shared/auth/ui/ErrorMessage";
 import EmailPasswordForm from "@app/routes/login/EmailPasswordForm";
 import OAuthButtons from "@app/routes/login/OAuthButtons";
 import LoggedInState from "@app/routes/login/LoggedInState";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 export default function Login() {
   const navigate = useNavigate();

frontend/editor/src/saas/routes/OAuthConsent.tsx

@@ -8,7 +8,7 @@ import "@shared/auth/ui/auth.css";
 import "@app/routes/authShared/saas-auth.css";
 import { withBasePath } from "@app/constants/app";
 import ErrorMessage from "@shared/auth/ui/ErrorMessage";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 /**
  * OAuth 2.1 consent screen for the Supabase OAuth server (used by MCP clients

frontend/editor/src/saas/routes/Signup.tsx

@@ -19,7 +19,7 @@ import {
   SignupFieldErrors,
 } from "@app/routes/signup/SignupFormValidation";
 import { useAuthService } from "@app/routes/signup/AuthService";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 export default function Signup() {
   const navigate = useNavigate();

frontend/editor/vite.config.ts

@@ -271,6 +271,17 @@ export default defineConfig(async ({ mode }) => {
             src: "../node_modules/pdfjs-dist/standard_fonts/*",
             dest: "pdfjs/standard_fonts",
           },
+          {
+            // Brand assets live in the shared design system; the editor serves
+            // them by URL per variant, so copy each set to the /{variant}-logo
+            // path its manifests, index.html and useLogoAssets resolve against.
+            src: "../shared/assets/brand/classic-logo/*",
+            dest: "classic-logo",
+          },
+          {
+            src: "../shared/assets/brand/modern-logo/*",
+            dest: "modern-logo",
+          },
         ],
       }),
       compressStaticCopyPlugin(),

frontend/portal/src/components/LoginScreen.tsx

@@ -7,7 +7,7 @@ import SpringLoginForm from "@shared/auth/ui/SpringLoginForm";
 import { useSpringLogin } from "@shared/auth/ui/useSpringLogin";
 import "@shared/auth/ui/auth-theme.css";
 import "@shared/auth/ui/auth.css";
-import loginHeader from "@shared/assets/login/LoginLightModeHeader.svg";
+import loginHeader from "@shared/assets/brand/modern-logo/LoginLightModeHeader.svg";
 
 /**
  * Full-screen login shown by the portal's auth gate. Renders the same screen as

frontend/portal/src/components/Sidebar.tsx

@@ -8,8 +8,8 @@ import { useLink } from "@portal/contexts/LinkContext";
 import { useAsync } from "@portal/hooks/useAsync";
 import { fetchHomeKpis, type KpiEntry } from "@portal/api/home";
 import { EDITOR_URL } from "@portal/auth/editorUrl";
-import markLight from "@shared/assets/stirling-mark-light.svg";
-import markDark from "@shared/assets/stirling-mark-dark.svg";
+import markLight from "@shared/assets/brand/modern-logo/StirlingPDFLogoNoTextLight.svg";
+import markDark from "@shared/assets/brand/modern-logo/StirlingPDFLogoNoTextDark.svg";
 import {
   HomeIcon,
   UsersIcon,

frontend/shared/assets/Brand.stories.tsx

@@ -0,0 +1,106 @@
+import type { Meta, StoryObj } from "@storybook/react-vite";
+
+// Visual catalogue of the shared brand assets (shared/assets/brand) — the single
+// source of truth for the Stirling logos used across the apps.
+import modernMarkDark from "@shared/assets/brand/modern-logo/StirlingPDFLogoNoTextDark.svg";
+import modernMarkLight from "@shared/assets/brand/modern-logo/StirlingPDFLogoNoTextLight.svg";
+import modernBlack from "@shared/assets/brand/modern-logo/StirlingPDFLogoBlackText.svg";
+import modernWhite from "@shared/assets/brand/modern-logo/StirlingPDFLogoWhiteText.svg";
+import modernGrey from "@shared/assets/brand/modern-logo/StirlingPDFLogoGreyText.svg";
+import classicMarkDark from "@shared/assets/brand/classic-logo/StirlingPDFLogoNoTextDark.svg";
+import classicMarkLight from "@shared/assets/brand/classic-logo/StirlingPDFLogoNoTextLight.svg";
+import classicBlack from "@shared/assets/brand/classic-logo/StirlingPDFLogoBlackText.svg";
+import classicWhite from "@shared/assets/brand/classic-logo/StirlingPDFLogoWhiteText.svg";
+import classicGrey from "@shared/assets/brand/classic-logo/StirlingPDFLogoGreyText.svg";
+
+type Asset = { label: string; src: string; onDark?: boolean };
+type VariantSet = { variant: string; mark: Asset[]; wordmark: Asset[] };
+
+const SETS: VariantSet[] = [
+  {
+    variant: "modern",
+    mark: [
+      { label: "NoTextDark", src: modernMarkDark },
+      { label: "NoTextLight", src: modernMarkLight, onDark: true },
+    ],
+    wordmark: [
+      { label: "BlackText", src: modernBlack },
+      { label: "GreyText", src: modernGrey },
+      { label: "WhiteText", src: modernWhite, onDark: true },
+    ],
+  },
+  {
+    variant: "classic",
+    mark: [
+      { label: "NoTextDark", src: classicMarkDark },
+      { label: "NoTextLight", src: classicMarkLight, onDark: true },
+    ],
+    wordmark: [
+      { label: "BlackText", src: classicBlack },
+      { label: "GreyText", src: classicGrey },
+      { label: "WhiteText", src: classicWhite, onDark: true },
+    ],
+  },
+];
+
+function Swatch({ label, src, onDark, h }: Asset & { h: number }) {
+  return (
+    <figure
+      style={{ margin: 0, display: "grid", gap: 6, justifyItems: "center" }}
+    >
+      <div
+        style={{
+          display: "grid",
+          placeItems: "center",
+          padding: 16,
+          minWidth: 140,
+          borderRadius: 8,
+          border: "1px solid rgba(128,128,128,0.25)",
+          background: onDark ? "#1a1a1a" : "#ffffff",
+        }}
+      >
+        <img src={src} alt={label} style={{ height: h, maxWidth: 200 }} />
+      </div>
+      <figcaption style={{ fontSize: 12, color: "var(--text-muted, #71717a)" }}>
+        {label}
+      </figcaption>
+    </figure>
+  );
+}
+
+function Row({ title, items }: { title: string; items: Asset[] }) {
+  return (
+    <div style={{ display: "grid", gap: 8 }}>
+      <h4 style={{ margin: 0, textTransform: "capitalize" }}>{title}</h4>
+      <div style={{ display: "flex", gap: 16, flexWrap: "wrap" }}>
+        {items.map((a) => (
+          <Swatch key={a.label} {...a} h={title === "mark" ? 48 : 28} />
+        ))}
+      </div>
+    </div>
+  );
+}
+
+const meta: Meta = {
+  title: "Brand/Logos",
+  parameters: { layout: "padded" },
+};
+export default meta;
+type Story = StoryObj;
+
+/** Every brand mark + wordmark, per variant, on the background each is built for. */
+export const Logos: Story = {
+  render: () => (
+    <div style={{ display: "grid", gap: 32 }}>
+      {SETS.map((set) => (
+        <section key={set.variant} style={{ display: "grid", gap: 16 }}>
+          <h3 style={{ margin: 0, textTransform: "capitalize" }}>
+            {set.variant}
+          </h3>
+          <Row title="mark" items={set.mark} />
+          <Row title="wordmark" items={set.wordmark} />
+        </section>
+      ))}
+    </div>
+  ),
+};

frontend/shared/assets/stirling-mark-dark.svg

@@ -1,4 +0,0 @@
-<svg width="92" height="100" viewBox="0 0 92 100" fill="none" xmlns="http://www.w3.org/2000/svg">
-<path d="M0 50L60 0V46.5L0 96.5V50Z" fill="#E6E6E6" fill-opacity="0.4"/>
-<path d="M32 53L92 3V49.5L32 99.5V53Z" fill="#E6E6E6" fill-opacity="0.7"/>
-</svg>

frontend/shared/assets/stirling-mark-light.svg

@@ -1,4 +0,0 @@
-<svg width="92" height="100" viewBox="0 0 92 100" fill="none" xmlns="http://www.w3.org/2000/svg">
-<path d="M0 50L60 0V46.5L0 96.5V50Z" fill="#ACACAC" fill-opacity="0.3"/>
-<path d="M32 53L92 3V49.5L32 99.5V53Z" fill="#FC9999" fill-opacity="0.5"/>
-</svg>