fix: resolve TypeScript errors in CI type-check

- next.config.ts: cssChunking 'loose' → false ('loose' not in type)
- ActivityFeed.test.tsx: remove always-truthy TS2872 literal expression

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

app/__tests__/components/ActivityFeed.test.tsx

@@ -58,7 +58,7 @@ describe('ActivityFeed NaN Handling', () => {
     });
 
     it('should convert gaming.name to string safely', () => {
-      const validName = String('Test Game' || '');
+      const validName = String('Test Game');
       expect(validName).toBe('Test Game');
       expect(typeof validName).toBe('string');
 

next.config.ts

@@ -36,7 +36,7 @@ const nextConfig: NextConfig = {
     optimizePackageImports: ["lucide-react", "framer-motion", "react-icons", "@tiptap/react"],
     // Merge all CSS into a single chunk to eliminate the render-blocking CSS chain
     // (84dc7384.css → 3aefc04b.css sequential dependency reported by PageSpeed).
-    cssChunking: "loose",
+    cssChunking: false,
     // Note: optimizeCss (critters) is intentionally disabled — it converts the main
     // <link rel="stylesheet"> to a JS-deferred preload, which PageSpeed reads as a
     // sequential CSS chain and reports 410ms of render-blocking.