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>

app/modules/auth/models.py

@@ -0,0 +1,31 @@
+"""SQLAlchemy models for authentication
+
+資料表結構：
+- user_sessions: 儲存使用者 session 資料，包含加密密碼用於自動刷新
+"""
+from sqlalchemy import Column, Integer, String, DateTime, Index
+from datetime import datetime
+from app.core.database import Base
+
+
+class UserSession(Base):
+    """User session model with encrypted password for auto-refresh"""
+
+    __tablename__ = "user_sessions"
+
+    id = Column(Integer, primary_key=True, index=True)
+    username = Column(String(255), nullable=False, comment="User email from AD")
+    display_name = Column(String(255), nullable=False, comment="Display name for chat")
+    internal_token = Column(
+        String(255), unique=True, nullable=False, index=True, comment="Internal session token (UUID)"
+    )
+    ad_token = Column(String(500), nullable=False, comment="AD API token")
+    encrypted_password = Column(String(500), nullable=False, comment="AES-256 encrypted password")
+    ad_token_expires_at = Column(DateTime, nullable=False, comment="AD token expiry time")
+    refresh_attempt_count = Column(
+        Integer, default=0, nullable=False, comment="Failed refresh attempts counter"
+    )
+    last_activity = Column(
+        DateTime, default=datetime.utcnow, nullable=False, comment="Last API request time"
+    )
+    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)