feat: apply KBX Foundation v4 pattern to home navigation

1. Create home feature registry (registry.ts)
   - Define homeScreen: KbxScreenDefinition
   - screenId: "home.dashboard"
   - Module: "Home"
   - Type: "dashboard"
   - Accessible to all users (no permissions required)

2. Update central registry (registry/screens.ts)
   - Import homeScreens from home/registry
   - Add homeScreens to getAllScreens()
   - Prepare for dynamic screen loading

3. Refactor HomePage.vue (KBX pattern)
   - Replace navigationCatalog with registry-driven screens
   - Use useKbxRegistry() composable
   - Dynamic module grouping from registry
   - Favorites/recent workbench
   - Attention items aggregation (DEBT-030)

4. Extend module types (kbx-types.ts)
   - Add "Home" to module union type
   - Support existing modules: Research, Operations, Portfolio, etc.
   - Flexible module extensibility

Features:
- Registry-driven navigation
- Centralized screen definitions
- Dynamic module grouping and sorting
- Favorites/recent screen tracking
- Type-safe screen lookups
- Zero hardcoded navigation paths

Benefits:
- Single source of truth for screen registry
- Automatic sync with router definitions
- Easy to add new modules
- Maintainable and testable

TypeScript: ✅ PASS (0 errors)
Typecheck time: ~5s

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontend/src/registry/screens.ts

@@ -4,9 +4,9 @@
  */
 
 import type { KbxScreenDefinition } from '@shared/contracts/kbx-types'
+import { homeScreens } from '@features/home/registry'
 
 // Import screen definitions from each feature module
-// (these will be created in Task 4)
 // import { shadowRunScreens } from '@features/shadow-run/registry'
 // import { modelScreens } from '@features/models/registry'
 
@@ -61,7 +61,8 @@ export const exampleScreens: KbxScreenDefinition[] = [
 export function getAllScreens(): KbxScreenDefinition[] {
   const screens: KbxScreenDefinition[] = []
 
-  // Add screens from all modules (to be populated as features are created)
+  // Add screens from all modules
+  screens.push(...homeScreens)
   // screens.push(...shadowRunScreens)
   // screens.push(...modelScreens)