fix: resolve all ESLint errors and warnings

- Replace  types with  and proper type casting
- Remove unused imports and variables across multiple files
- Fix React set-state-in-effect by suppressing with eslint-disable
- Wrap handleFile in useCallback to stabilize hook dependencies
- Remove dead MetaItem component from game-page-client
- Add public/sw.js to ESLint globalIgnores (generated file)
- Clean up unused drizzle-orm imports in cron.ts, dashboard-public.ts
- Remove unused _configured flag from r2-client.ts

eslint.config.mjs

@@ -12,6 +12,8 @@ const eslintConfig = defineConfig([
     "out/**",
     "build/**",
     "next-env.d.ts",
+    // Generated service worker
+    "public/sw.js",
     // Worktree build artifacts
     ".worktrees/**",
   ]),