feat: Initial commit - Task Reporter incident response system

Complete implementation of the production line incident response system (生產線異常即時反應系統) including:

Backend (FastAPI):
- User authentication with AD integration and session management
- Chat room management (create, list, update, members, roles)
- Real-time messaging via WebSocket (typing indicators, reactions)
- File storage with MinIO (upload, download, image preview)

Frontend (React + Vite):
- Authentication flow with token management
- Room list with filtering, search, and pagination
- Real-time chat interface with WebSocket
- File upload with drag-and-drop and image preview
- Member management and room settings
- Breadcrumb navigation
- 53 unit tests (Vitest)

Specifications:
- authentication: AD auth, sessions, JWT tokens
- chat-room: rooms, members, templates
- realtime-messaging: WebSocket, messages, reactions
- file-storage: MinIO integration, file management
- frontend-core: React SPA structure

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

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

openspec/changes/archive/2025-12-01-add-react-frontend/proposal.md

@@ -0,0 +1,31 @@
+# Change: Add React Frontend Application
+
+## Why
+The Task Reporter system currently has a complete backend API but no user interface. Users cannot interact with the incident response system without a frontend application. A React-based SPA will enable production line operators, supervisors, and engineers to create incident rooms, collaborate in real-time, upload evidence files, and manage incident resolution.
+
+## What Changes
+- **NEW**: React 18 + Vite frontend application
+- **NEW**: Authentication flow (login/logout with token management)
+- **NEW**: Incident room management UI (create, list, view, update)
+- **NEW**: Real-time chat interface with WebSocket integration
+- **NEW**: File upload/download interface with image preview
+- **NEW**: Member management UI (add, remove, change roles)
+- **NEW**: Responsive layout for desktop and tablet use
+
+## Impact
+- Affected specs: Creates new `frontend-core` specification
+- Affected code:
+  - New `frontend/` directory with React application
+  - Backend CORS configuration update (app/main.py)
+  - Static file serving configuration
+
+## Dependencies
+- Backend API must be running (localhost:8000)
+- MinIO must be running for file uploads (localhost:9000)
+
+## Success Criteria
+1. Users can login with AD credentials
+2. Users can create and join incident rooms
+3. Users can send/receive messages in real-time
+4. Users can upload and view files (images, PDFs, logs)
+5. Room owners can manage members and room status