feat: refactor monolithic App.vue into modular Vue component architecture

- Extract 711-line App.vue into 15+ focused files across 5 directories
- Add data layer (icons, metrics, policies, auditTrail, requests)
- Add composables (useNavigation, useRequests, useChat, useToast)
- Add layout components (SidebarRail, TopBar, FilterBar)
- Add shared components (PanelHead, InfoRow, ToastNotification)
- Add business component (RequestTable) and 5 view components
- Extract global CSS to assets/styles/global.css
- Add start.sh with WSL/Windows cross-platform support
- Add .gitignore for node_modules, dist, and IDE dirs

src/main.js

@@ -0,0 +1,5 @@
+import { createApp } from 'vue'
+import { MotionPlugin } from '@vueuse/motion'
+import App from './App.vue'
+
+createApp(App).use(MotionPlugin).mount('#app')