feat: complete issue fixes and implement remaining features

## Critical Issues (CRIT-001~003) - All Fixed
- JWT secret key validation with pydantic field_validator
- Login audit logging for success/failure attempts
- Frontend API path prefix removal

## High Priority Issues (HIGH-001~008) - All Fixed
- Project soft delete using is_active flag
- Redis session token bytes handling
- Rate limiting with slowapi (5 req/min for login)
- Attachment API permission checks
- Kanban view with drag-and-drop
- Workload heatmap UI (WorkloadPage, WorkloadHeatmap)
- TaskDetailModal integrating Comments/Attachments
- UserSelect component for task assignment

## Medium Priority Issues (MED-001~012) - All Fixed
- MED-001~005: DB commits, N+1 queries, datetime, error format, blocker flag
- MED-006: Project health dashboard (HealthService, ProjectHealthPage)
- MED-007: Capacity update API (PUT /api/users/{id}/capacity)
- MED-008: Schedule triggers (cron parsing, deadline reminders)
- MED-009: Watermark feature (image/PDF watermarking)
- MED-010~012: useEffect deps, DOM operations, PDF export

## New Files
- backend/app/api/health/ - Project health API
- backend/app/services/health_service.py
- backend/app/services/trigger_scheduler.py
- backend/app/services/watermark_service.py
- backend/app/core/rate_limiter.py
- frontend/src/pages/ProjectHealthPage.tsx
- frontend/src/components/ProjectHealthCard.tsx
- frontend/src/components/KanbanBoard.tsx
- frontend/src/components/WorkloadHeatmap.tsx

## Tests
- 113 new tests passing (health: 32, users: 14, triggers: 35, watermark: 32)

## OpenSpec Archives
- add-project-health-dashboard
- add-capacity-update-api
- add-schedule-triggers
- add-watermark-feature
- add-rate-limiting
- enhance-frontend-ux
- add-resource-management-ui

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/services/projectHealth.ts

@@ -0,0 +1,60 @@
+import api from './api'
+
+// Types for Project Health API responses
+export type RiskLevel = 'low' | 'medium' | 'high' | 'critical'
+export type ScheduleStatus = 'on_track' | 'at_risk' | 'delayed'
+export type ResourceStatus = 'adequate' | 'constrained' | 'overloaded'
+
+export interface ProjectHealthItem {
+  id: string
+  project_id: string
+  health_score: number
+  risk_level: RiskLevel
+  schedule_status: ScheduleStatus
+  resource_status: ResourceStatus
+  last_updated: string
+  project_title: string
+  project_status: string
+  owner_name: string | null
+  space_name: string | null
+  task_count: number
+  completed_task_count: number
+  blocker_count: number
+  overdue_task_count: number
+}
+
+export interface ProjectHealthSummary {
+  total_projects: number
+  healthy_count: number
+  at_risk_count: number
+  critical_count: number
+  average_health_score: number
+  projects_with_blockers: number
+  projects_delayed: number
+}
+
+export interface ProjectHealthDashboardResponse {
+  projects: ProjectHealthItem[]
+  summary: ProjectHealthSummary
+}
+
+// API functions
+export const projectHealthApi = {
+  /**
+   * Get project health dashboard with all projects
+   */
+  getDashboard: async (): Promise<ProjectHealthDashboardResponse> => {
+    const response = await api.get<ProjectHealthDashboardResponse>('/projects/health/dashboard')
+    return response.data
+  },
+
+  /**
+   * Get health status for a single project
+   */
+  getProjectHealth: async (projectId: string): Promise<ProjectHealthItem> => {
+    const response = await api.get<ProjectHealthItem>(`/projects/health/${projectId}`)
+    return response.data
+  },
+}
+
+export default projectHealthApi