🔧 Fix CORS and API endpoint issues

- Fix API endpoint paths (remove trailing slashes for 405 errors)
- Update API URLs to use api-todo.hyungi.net subdomain for HTTPS compatibility
- Improve CORS settings parsing in backend (handle brackets and quotes)
- Add frontend volume mount to docker-compose for real-time file updates
- Update Synology deployment config with wildcard CORS settings

Resolves:
- 405 Method Not Allowed errors
- Mixed Content security issues (HTTPS → HTTP)
- CORS preflight request failures
- Docker build requirements for every file change

Tested: API endpoints now correctly use HTTPS subdomain, eliminating security blocks

docker-compose.dev.yml

@@ -0,0 +1,64 @@
+services:
+  frontend:
+    image: nginx:alpine
+    ports:
+      - "${FRONTEND_PORT:-4000}:80"
+    volumes:
+      # 프론트엔드 파일 실시간 반영
+      - ./frontend:/usr/share/nginx/html
+      - ./frontend/nginx.conf:/etc/nginx/nginx.conf
+    depends_on:
+      - backend
+    restart: unless-stopped
+    networks:
+      - todo-network
+
+  backend:
+    build:
+      context: ./backend
+      dockerfile: Dockerfile
+    ports:
+      - "${BACKEND_PORT:-9000}:9000"
+    depends_on:
+      database:
+        condition: service_healthy
+    environment:
+      - DATABASE_URL=postgresql+asyncpg://todo_user:${POSTGRES_PASSWORD:-todo_password}@database:5432/todo_db
+      - SECRET_KEY=${SECRET_KEY:-your-secret-key-change-this-in-production}
+      - DEBUG=${DEBUG:-false}
+      - CORS_ORIGINS=${CORS_ORIGINS:-*}
+    volumes:
+      # 시놀로지 볼륨 매핑
+      - ${SYNOLOGY_UPLOADS_PATH:-/volume1/todo-project/uploads}:/data/uploads
+      - ${SYNOLOGY_CONFIG_PATH:-/volume3/docker/todo-project/config}:/app/config
+      # 백엔드 소스 실시간 반영
+      - ./backend/src:/app/src
+    restart: unless-stopped
+    networks:
+      - todo-network
+
+  database:
+    image: postgres:15-alpine
+    ports:
+      - "${DATABASE_PORT:-5432}:5432"
+    environment:
+      - POSTGRES_USER=${POSTGRES_USER:-todo_user}
+      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD:-todo_password}
+      - POSTGRES_DB=${POSTGRES_DB:-todo_db}
+    volumes:
+      # 시놀로지 볼륨 매핑
+      - ${SYNOLOGY_DB_PATH:-/volume3/docker/todo-project/postgres}:/var/lib/postgresql/data
+      - ${SYNOLOGY_CONFIG_PATH:-/volume3/docker/todo-project/config}/migrations:/docker-entrypoint-initdb.d
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER:-todo_user} -d ${POSTGRES_DB:-todo_db}"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 30s
+    networks:
+      - todo-network
+
+networks:
+  todo-network:
+    driver: bridge