feat: Add AI report generation with DIFY integration

- Add Users table for display name resolution from AD authentication
- Integrate DIFY AI service for report content generation
- Create docx assembly service with image embedding from MinIO
- Add REST API endpoints for report generation and download
- Add WebSocket notifications for generation progress
- Add frontend UI with progress modal and download functionality
- Add integration tests for report generation flow

Report sections (Traditional Chinese):
- 事件摘要 (Summary)
- 時間軸 (Timeline)
- 參與人員 (Participants)
- 處理過程 (Resolution Process)
- 目前狀態 (Current Status)
- 最終處置結果 (Final Resolution)

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

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

app/modules/auth/router.py

@@ -11,6 +11,7 @@ from app.modules.auth.schemas import LoginRequest, LoginResponse, LogoutResponse
 from app.modules.auth.services.ad_client import ad_auth_service
 from app.modules.auth.services.encryption import encryption_service
 from app.modules.auth.services.session_service import session_service
+from app.modules.auth.services.user_service import upsert_user
 from fastapi import Header
 from typing import Optional
 
@@ -30,10 +31,11 @@ async def login(request: LoginRequest, db: Session = Depends(get_db)):
 
     流程：
     1. 呼叫 AD API 驗證憑證
-    2. 加密密碼（用於自動刷新）
-    3. 生成 internal token (UUID)
-    4. 儲存 session 到資料庫
-    5. 回傳 internal token 和 display_name
+    2. 儲存/更新使用者資訊到 users 表（用於報告姓名解析）
+    3. 加密密碼（用於自動刷新）
+    4. 生成 internal token (UUID)
+    5. 儲存 session 到資料庫
+    6. 回傳 internal token 和 display_name
     """
     try:
         # Step 1: Authenticate with AD API
@@ -52,10 +54,19 @@ async def login(request: LoginRequest, db: Session = Depends(get_db)):
             detail="Authentication service unavailable",
         )
 
-    # Step 2: Encrypt password for future auto-refresh
+    # Step 2: Upsert user info for report generation (permanent storage)
+    upsert_user(
+        db=db,
+        user_id=ad_result["email"],
+        display_name=ad_result["username"],
+        office_location=ad_result.get("office_location"),
+        job_title=ad_result.get("job_title"),
+    )
+
+    # Step 3: Encrypt password for future auto-refresh
     encrypted_password = encryption_service.encrypt_password(request.password)
 
-    # Step 3 & 4: Generate internal token and create session
+    # Step 4 & 5: Generate internal token and create session
     user_session = session_service.create_session(
         db=db,
         username=request.username,