Fix all ESLint errors: remove unused imports, replace any types

- Remove ~60 unused imports and variables across 88 files
- Replace ~80 `any` type annotations with proper types (unknown,
  Record<string, unknown>, or specific types)
- Prefix unused callback args with underscore
- Fix unescaped JSX entities
- Lint now passes cleanly (0 errors, 2 intentional img warnings)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/hooks/use-realtime-invalidation.ts

@@ -34,13 +34,13 @@ export function useRealtimeInvalidation(
           queryClient.invalidateQueries({ queryKey: key });
         }
       };
-      socket.on(event as any, handler);
+      socket.on(event, handler);
       handlers.push({ event, handler });
     }
 
     return () => {
       for (const { event, handler } of handlers) {
-        socket.off(event as any, handler);
+        socket.off(event, handler);
       }
     };
   }, [socket, queryClient, eventMap]);