Search the whole document in Find, and stop negative charcode caches sticking

frontend/editor/src/core/tools/pdfTextEditor/v2/charcode/BackendResolver.ts

@@ -240,10 +240,12 @@ function maybeAutoPrefetch(
               }
 
               // Stop the per-keystroke prefetch storm. resolve looks these
-              // chars up under the QUERIED font, not perCharFont.
+              // chars up under the QUERIED font, not perCharFont. Use the
+              // TTL'd null: this font was never actually asked, so a permanent
+              // null would kill the pair for the rest of the session.
               if (perCharFont !== fontPtr) {
                 for (const ch of fontChars) {
-                  charCache.set(cacheKey(fontPtr, ch), null);
+                  setTransientNull(cacheKey(fontPtr, ch));
                 }
               }
             }

frontend/editor/src/core/tools/pdfTextEditor/v2/commands/editTextHelpers.ts

@@ -140,8 +140,12 @@ export function charcodesResolveFully(
     } catch {
       ok = false;
     }
-    perFont.set(ch, ok);
-    if (!ok) return false;
+    // Only memoise a POSITIVE result. A miss here can simply mean the
+    // charcode cache was cold or the backend was briefly unreachable, and
+    // caching that as "this font cannot encode this character" made the
+    // failure permanent for the session.
+    if (ok) perFont.set(ch, true);
+    else return false;
   }
   return true;
 }

frontend/editor/src/core/tools/pdfTextEditor/v2/components/FindBar.tsx

@@ -13,6 +13,7 @@ import type {
   MatchOptions,
   TextMatch,
 } from "@app/tools/pdfTextEditor/v2/util/textMatching";
+import { ensureAllPagesRead } from "@app/tools/pdfTextEditor/v2/hooks/useDocumentLoader";
 import type { EditorStore } from "@app/tools/pdfTextEditor/v2/store/EditorStore";
 import type {
   PageSnapshot,
@@ -60,6 +61,14 @@ export function FindBar({ store, pages, onClose }: FindBarProps) {
     inputRef.current?.focus();
   }, []);
 
+  // Opening Find is a document-wide request, so pull in every page that lazy
+  // loading has not read yet. Yield first: the read is synchronous, and on a
+  // long document it would otherwise block before the bar has painted.
+  useEffect(() => {
+    const id = setTimeout(() => ensureAllPagesRead(store), 0);
+    return () => clearTimeout(id);
+  }, [store]);
+
   const options: MatchOptions = useMemo(
     () => ({ matchCase, wholeWord, ignoreAccents }),
     [matchCase, wholeWord, ignoreAccents],