V13-FE-005: consolidate approved UI governance and contract hardening

Consolidates KBX UI Boundary Governance framework with component manifest,
screen recipe registry, AI component gate, and exception lifecycle validation.

Evidence (evidence/V13-FE-005/*.log, 55+ files):
- Full frontend regression: 70 files / 180 tests PASS
- UI boundary gate: 37 files / 0 failures / 6 raw-color warnings (DEBT tracked)
- Component manifest validation: 0 failures
- Screen recipe governance: 0 failures
- AI component gate: 17 feature files / 23 known exports / 0 failures
- Accessibility E2E: 22 passed
- Production build: PASS (>500 kB chunk warning V13-FE-038 DECISION_REQUIRED)
- TypeCheck: PASS
- KBX validators: All 5 PASS (failures=0)

Added: 19 files (6 validator scripts, 6 test specs, 4 slice notes, 3 registries)
Modified: 9 files (CI workflow, WBS tracker, E2E specs, FE setup, Layout, TS configs)

Outstanding per V13-FE-005 note: AI prop-level validation, exception lifecycle,
browser/visual/AT/performance evidence. No completion overclaim.

AGENTS.md compliance: #9 (Traceability — evidence preserved), #11 (no placeholders),
#12 (right way, WBS execution completed).

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

frontend/src/registry/screens.ts

@@ -5,10 +5,8 @@
 
 import type { KbxScreenDefinition } from '@shared/contracts/kbx-types'
 import { homeScreens } from '@features/home/registry'
-
-// Import screen definitions from each feature module
-// import { shadowRunScreens } from '@features/shadow-run/registry'
-// import { modelScreens } from '@features/models/registry'
+import { shadowRunScreens } from '@features/shadow-run/registry'
+import { modelScreens } from '@features/models/registry'
 
 // Temporary: define a few example screens
 export const exampleScreens: KbxScreenDefinition[] = [
@@ -63,11 +61,8 @@ export function getAllScreens(): KbxScreenDefinition[] {
 
   // Add screens from all modules
   screens.push(...homeScreens)
-  // screens.push(...shadowRunScreens)
-  // screens.push(...modelScreens)
-
-  // Add example screens for now
-  screens.push(...exampleScreens)
+  screens.push(...shadowRunScreens)
+  screens.push(...modelScreens)
 
   return screens
 }