revert: Remove debugging infrastructure while keeping bug fixes

Removed:
- ErrorBoundary component and all error boundary wrapping
- Debug console.log statements from useReasoningTranslation
- Debug useEffect in DashboardPage
- Dev mode Dockerfile (Dockerfile.kubernetes.dev)
- Dev mode Tilt configuration
- Enhanced vite watcher config (depth, awaitWriteFinish, HMR overlay)

Kept actual bug fixes:
- String() coercion in translation functions
- useMemo/useCallback for formatters
- Null guards in components
- Basic vite ignored patterns (node_modules, dist, .git)
- Conditional rendering in DashboardPage

frontend/vite.config.ts

@@ -24,14 +24,12 @@ export default defineConfig({
     host: '0.0.0.0', // Important for Docker
     port: 3000,
     watch: {
-      usePolling: true, // Important for Docker file watching
-      // Ignore these directories to prevent "too many open files" error in Kubernetes
+      // Use polling for Docker/Kubernetes compatibility
+      usePolling: true,
       ignored: [
         '**/node_modules/**',
         '**/dist/**',
         '**/.git/**',
-        '**/coverage/**',
-        '**/.cache/**',
       ],
     },
     proxy: {