fix(profile): private notes no longer lose typed text

The store-sync effect re-applied the stored note on every notification,
including the echo of the note's own save, reverting text typed after
the debounce fired; and closing the panel inside the 800ms debounce
dropped the pending save. Add a dirty ref that suppresses the resync
while there are unsaved edits, and flush the pending save on unmount.

Fixes #18

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/components/user-profile/UserRoomProfile.tsx

@@ -214,24 +214,56 @@ function UserPrivateNotes({ userId }: { userId: string }) {
   const [draft, setDraft] = useState(() => getNote(userId));
   const [saving, setSaving] = useState(false);
   const saveTimer = useRef<ReturnType<typeof setTimeout> | undefined>(undefined);
+  // True while the user has unsaved local edits — prevents the store-sync
+  // effect below from reacting to the echo of our own save and reverting text
+  // typed after the debounce fired but before that save's account-data echo
+  // landed (mirrors statusDirtyRef in Profile.tsx's ProfileStatus).
+  const dirtyRef = useRef(false);
+  // Latest draft/userId, kept current on every render so the unmount cleanup
+  // can flush a pending save without capturing a stale closure.
+  const draftRef = useRef(draft);
+  draftRef.current = draft;
+  const userIdRef = useRef(userId);
+  userIdRef.current = userId;
+  const setNoteRef = useRef(setNote);
+  setNoteRef.current = setNote;
+  const prevUserIdRef = useRef(userId);
 
-  // Sync if account data arrives after mount
+  // Sync if account data arrives after mount, but never while there are
+  // unsaved local edits (including our own save's in-flight echo).
   useEffect(() => {
+    if (prevUserIdRef.current !== userId) {
+      prevUserIdRef.current = userId;
+      dirtyRef.current = false;
+    }
+    if (dirtyRef.current) return;
     setDraft(getNote(userId));
   }, [getNote, userId]);
 
   const handleChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
     const val = e.target.value;
+    dirtyRef.current = true;
     setDraft(val);
     clearTimeout(saveTimer.current);
     saveTimer.current = setTimeout(async () => {
+      dirtyRef.current = false;
       setSaving(true);
       await setNote(userId, val);
       setSaving(false);
     }, 800);
   };
 
-  useEffect(() => () => clearTimeout(saveTimer.current), []);
+  useEffect(
+    () => () => {
+      clearTimeout(saveTimer.current);
+      // Flush a still-pending debounced save instead of dropping it (e.g. the
+      // profile panel closes within the 800ms debounce window).
+      if (dirtyRef.current) {
+        setNoteRef.current(userIdRef.current, draftRef.current);
+      }
+    },
+    [],
+  );
 
   const charsLeft = USER_NOTE_MAX_LENGTH - draft.length;