feat: add Docker deployment support

Add Dockerfile (python:3.11-slim), docker-compose.yml with volume mounts for webui/data/logs, and .dockerignore for minimal image size.

Made-with: Cursor

docker-compose.yml

@@ -0,0 +1,14 @@
+services:
+  elysia-todo:
+    build: .
+    container_name: elysia-todo
+    restart: unless-stopped
+    ports:
+      - "23994:23994"
+    volumes:
+      # 挂载前端编译产物，本地修改后可立即生效
+      - ./api/webui:/app/api/webui:ro
+      # 挂载数据库文件，持久化数据
+      - ./api/data:/app/api/data
+      # 挂载日志目录，方便查看日志
+      - ./api/logs:/app/api/logs