feat: Phase 2 — frontend-backend integration complete

- All 5 core pages now use real API instead of mock data
  - Dashboard: /api/v1/dashboard/stats
  - Tickets: list/create/detail/approve/execute/statistics
  - Users: list/create/toggle-active/delete
  - Instances: list/create/test-connection/delete
  - Queries: execute with result display + sensitive field masking
- Updated DashboardStats type to match backend schema
- Fixed InstancePage to work with InstanceResponse (no qps/cpu/metrics yet)
- Added create forms for Tickets, Users, Instances
- Added connection test in InstanceDetail
- Updated TDD_PLAN.md: Phase 1 ✅ (44 tests), Phase 2 ✅
- Updated ROADMAP.md: v0.2.0 ✅
- Updated PROJECT_EVALUATION.md: score 5.7 → 6.2
- Frontend build passes with zero TS errors
- 44 backend tests still passing

frontend/src/lib/mock.ts

@@ -1,14 +1,14 @@
 import type { Ticket, DBInstance, QueryAudit, AuditRule, Workflow, NotificationChannel, Role, User, DataPermission, PermissionNode, DashboardStats } from '@/types';
 
 export const dashboardStats: DashboardStats = {
-  todayTickets: 128,
-  todayTicketsTrend: 12,
-  pendingApproval: 23,
-  pendingTrend: -5,
-  queryAuditCount: 15234,
-  queryTrend: 8,
-  slowQueries: 47,
-  slowQueryTrend: -12,
+  ticket_total: 128,
+  ticket_pending: 23,
+  ticket_month: 342,
+  ticket_executing: 3,
+  instance_total: 11,
+  instance_online: 8,
+  user_total: 7,
+  queries_today: 15234,
 };
 
 export const menuSections = [