feat: Migrate to MySQL and add unified environment configuration

## Database Migration (SQLite → MySQL)
- Add Alembic migration framework
- Add 'tr_' prefix to all tables to avoid conflicts in shared database
- Remove SQLite support, use MySQL exclusively
- Add pymysql driver dependency
- Change ad_token column to Text type for long JWT tokens

## Unified Environment Configuration
- Centralize all hardcoded settings to environment variables
- Backend: Extend Settings class in app/core/config.py
- Frontend: Use Vite environment variables (import.meta.env)
- Docker: Move credentials to environment variables
- Update .env.example files with comprehensive documentation

## Test Organization
- Move root-level test files to tests/ directory:
  - test_chat_room.py → tests/test_chat_room.py
  - test_websocket.py → tests/test_websocket.py
  - test_realtime_implementation.py → tests/test_realtime_implementation.py
- Fix path references in test_realtime_implementation.py

Breaking Changes:
- CORS now requires explicit origins (no more wildcard)
- All database tables renamed with 'tr_' prefix
- SQLite no longer supported

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

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

app/modules/file_storage/models.py

@@ -8,13 +8,13 @@ from app.core.database import Base
 class RoomFile(Base):
     """File uploaded to an incident room"""
 
-    __tablename__ = "room_files"
+    __tablename__ = "tr_room_files"
 
     # Primary key
     file_id = Column(String(36), primary_key=True)
 
     # Foreign key to incident room (CASCADE delete when room is permanently deleted)
-    room_id = Column(String(36), ForeignKey("incident_rooms.room_id", ondelete="CASCADE"), nullable=False)
+    room_id = Column(String(36), ForeignKey("tr_incident_rooms.room_id", ondelete="CASCADE"), nullable=False)
 
     # File metadata
     uploader_id = Column(String(255), nullable=False)
@@ -36,8 +36,8 @@ class RoomFile(Base):
 
     # Indexes
     __table_args__ = (
-        Index("ix_room_files", "room_id", "uploaded_at"),
-        Index("ix_file_uploader", "uploader_id"),
+        Index("ix_tr_room_files_room_uploaded", "room_id", "uploaded_at"),
+        Index("ix_tr_room_files_uploader", "uploader_id"),
     )
 
     def __repr__(self):

app/modules/file_storage/validators.py

@@ -4,7 +4,10 @@ from fastapi import UploadFile, HTTPException
 from typing import Set
 import logging
 
+from app.core.config import get_settings
+
 logger = logging.getLogger(__name__)
+settings = get_settings()
 
 # MIME type whitelists
 IMAGE_TYPES: Set[str] = {
@@ -22,11 +25,6 @@ LOG_TYPES: Set[str] = {
     "text/csv"
 }
 
-# File size limits (bytes)
-IMAGE_MAX_SIZE = 10 * 1024 * 1024  # 10MB
-DOCUMENT_MAX_SIZE = 20 * 1024 * 1024  # 20MB
-LOG_MAX_SIZE = 5 * 1024 * 1024  # 5MB
-
 
 def detect_mime_type(file_data: bytes) -> str:
     """
@@ -118,11 +116,11 @@ def get_file_type_and_limits(mime_type: str) -> tuple[str, int]:
         HTTPException if MIME type not recognized
     """
     if mime_type in IMAGE_TYPES:
-        return ("image", IMAGE_MAX_SIZE)
+        return ("image", settings.get_image_max_size_bytes())
     elif mime_type in DOCUMENT_TYPES:
-        return ("document", DOCUMENT_MAX_SIZE)
+        return ("document", settings.get_document_max_size_bytes())
     elif mime_type in LOG_TYPES:
-        return ("log", LOG_MAX_SIZE)
+        return ("log", settings.get_log_max_size_bytes())
     else:
         raise HTTPException(
             status_code=400,