Refactor and optimize templates and code structure

- Deleted outdated templates for epics, product brief, and requirements PRD.
- Introduced lazy loading for locale messages in i18n module to enhance performance.
- Updated main application bootstrap to parallelize CSRF token fetching and locale loading.
- Implemented code splitting for router configuration to optimize bundle size and loading times.
- Added WebSocket connection limits and rate limiting to improve server performance and prevent abuse.
- Enhanced input validation with compiled regex patterns for better performance and maintainability.

ccw/frontend/src/main.tsx

@@ -5,7 +5,7 @@ import './index.css'
 import 'react-grid-layout/css/styles.css'
 import 'react-resizable/css/styles.css'
 import 'xterm/css/xterm.css'
-import { initMessages, getInitialLocale, getMessages, type Locale } from './lib/i18n'
+import { loadMessagesForLocale, getInitialLocale } from './lib/i18n'
 import { logWebVitals } from './lib/webVitals'
 
 /**
@@ -29,17 +29,14 @@ async function bootstrapApplication() {
   const rootElement = document.getElementById('root')
   if (!rootElement) throw new Error('Failed to find the root element')
 
-  // Initialize CSRF token before any API calls
-  await initCsrfToken()
+  // Parallelize CSRF token fetch and locale detection (independent operations)
+  const [, locale] = await Promise.all([
+    initCsrfToken(),
+    getInitialLocale()
+  ])
 
-  // Initialize translation messages
-  await initMessages()
-
-  // Determine initial locale from browser/storage
-  const locale: Locale = getInitialLocale()
-
-  // Get messages for the initial locale
-  const messages = getMessages(locale)
+  // Load only the active locale's messages (lazy load secondary on demand)
+  const messages = await loadMessagesForLocale(locale)
 
   const root = createRoot(rootElement)
   root.render(