chore: upgrade TypeScript 4.9 to 5.9, ESLint 8.29 to 8.57, @typescript-eslint 5 to 7

Resolves all TS2345/TS2347/TS7006 type errors introduced by stricter TypeScript 5.x.
Fix Icons.Settings to Icons.Setting, cast account data returns, fix implicit any.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/state/typingMembers.ts

@@ -72,6 +72,8 @@ const timeoutReceipt = (
   return Date.now() - target.ts >= timeout;
 };
 
+const typingTimers = new Map<string, ReturnType<typeof setTimeout>>();
+
 export const roomIdToTypingMembersAtom = atom<
   IRoomIdToTypingMembers,
   [IRoomIdToTypingMembersAction],