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/file_storage/schemas.py

@@ -0,0 +1,74 @@
+"""Pydantic schemas for file storage operations"""
+from pydantic import BaseModel, Field, field_validator
+from typing import Optional, List
+from datetime import datetime
+from enum import Enum
+
+
+class FileType(str, Enum):
+    """File type enumeration"""
+    IMAGE = "image"
+    DOCUMENT = "document"
+    LOG = "log"
+
+
+class FileUploadResponse(BaseModel):
+    """Response after successful file upload"""
+    file_id: str
+    filename: str
+    file_type: FileType
+    file_size: int
+    mime_type: str
+    download_url: str  # Presigned URL
+    uploaded_at: datetime
+    uploader_id: str
+
+    class Config:
+        from_attributes = True
+
+
+class FileMetadata(BaseModel):
+    """File metadata response"""
+    file_id: str
+    room_id: str
+    filename: str
+    file_type: FileType
+    mime_type: str
+    file_size: int
+    minio_bucket: str
+    minio_object_path: str
+    uploaded_at: datetime
+    uploader_id: str
+    deleted_at: Optional[datetime] = None
+    download_url: Optional[str] = None  # Presigned URL (only when requested)
+
+    class Config:
+        from_attributes = True
+
+    @field_validator("file_size")
+    @classmethod
+    def validate_file_size(cls, v):
+        """Validate file size is positive"""
+        if v <= 0:
+            raise ValueError("File size must be positive")
+        return v
+
+
+class FileListResponse(BaseModel):
+    """Paginated file list response"""
+    files: List[FileMetadata]
+    total: int
+    limit: int
+    offset: int
+    has_more: bool
+
+    class Config:
+        from_attributes = True
+
+
+class FileUploadParams(BaseModel):
+    """Parameters for file upload (optional description)"""
+    description: Optional[str] = Field(None, max_length=500)
+
+    class Config:
+        from_attributes = True