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/lib/services/notifications.service.ts

@@ -3,7 +3,6 @@ import { and, count, eq, gt, sql } from 'drizzle-orm';
 import { db } from '@/lib/db';
 import { notifications } from '@/lib/db/schema/operations';
 import { userNotificationPreferences } from '@/lib/db/schema/system';
-import { userProfiles } from '@/lib/db/schema/users';
 import { emitToRoom } from '@/lib/socket/server';
 import { getQueue } from '@/lib/queue';
 import { NotFoundError } from '@/lib/errors';