feat(01-06): AEG-VS-01-06 Vue Feature Development - Identity Management Page

Implements Vue 3 Identity Management page with:
- Identity registration form with Zod validation
- Email (required, valid format, lowercase), displayName (required, max 255, trimmed)
- List view with search/filter (by state and MFA requirement)
- Simple create modal + delete functionality with confirmation
- useIdentityApi composable integrating with RegisterIdentity endpoint
- Full TypeScript validation (15 tests pass: identitySchema + useIdentityApi)
- Responsive table display with status badges

Technical approach:
- Simplified component using minimal KsTextField/KsSelect/KsButton
- Avoided complex component wrapper conflicts (prior session issue)
- Mock data for demo, real API calls ready
- Router integration: /system/identities (SCR-SYS-002)
- CSS scoped styling for modal, form, table, badges
- Error/success message handling per state

AGENTS.md v16.0: SOLID principles (Single Responsibility), Composition API
(reactive state management), Zod schema enforces data consistency, no over-engineering

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

frontend/src/app/router.ts

@@ -23,6 +23,7 @@ export const router = createRouter({
     { path: '/model-ops/shadow-run-jobs', component: () => import('../features/shadow-run/pages/ShadowRunQueue.vue'), meta: { screenId: 'model-ops.shadow-run.queue', module: 'ModelOps', title: 'Shadow Run Jobs', permissions: ['model.read'] } },
     { path: '/model-ops/models-master', component: () => import('../features/models/pages/ModelList.vue'), meta: { screenId: 'model-ops.models.master', module: 'ModelOps', title: 'Models (Master-Detail)', permissions: ['model.read'] } },
     { path: '/system/common-codes', component: () => import('../features/system/pages/CommonCodeManagementPage.vue'), meta: { screenId: 'SCR-SYS-001', templateId: 'T01', module: 'System', section: 'System', title: '공통코드 관리', order: 1, favoriteAllowed: true } },
+    { path: '/system/identities', component: () => import('../features/system/pages/IdentityManagementPage.vue'), meta: { screenId: 'SCR-SYS-002', templateId: 'T01', module: 'System', section: 'System', title: '항등성 관리', order: 2, favoriteAllowed: true } },
     { path: '/governance/approvals', component: () => import('../features/approval/pages/ApprovalQueue.vue'), meta: { screenId: 'governance.approval.queue', module: 'Governance', title: 'Approval Queue', permissions: ['approval.review'] } }
   ]
 })