refactor deployment config and exchange integrations

Simplify runtime configuration and remove legacy database and settings surface so new installs are easier to operate.
Refresh deployment assets, docs, and order execution behavior to keep the packaged app aligned with the current backend.

Made-with: Cursor

docker-compose.yml

@@ -8,19 +8,24 @@
 #   3. docker-compose up -d --build
 #   4. Open http://localhost:8888
 #
-# Frontend image: multi-stage build from QuantDinger-Vue-src (context = repo root).
-# To refresh static files without Docker: cd QuantDinger-Vue-src && npm run build
-#   && rm -rf ../frontend/dist && cp -R dist ../frontend/dist
+# Frontend image: nginx serving prebuilt files from `frontend/dist`.
+# The open-source repo does not require Node.js to build the frontend image.
 #
 # Note: The container will NOT start if SECRET_KEY is using the default value.
 #       This is a security measure to prevent insecure deployments.
+#
+# Docker image sources:
+#   Default uses official Docker Hub images.
+#   To switch source globally, set a single `IMAGE_PREFIX` in project-root `.env`.
+#   Examples: empty (official), `docker.m.daocloud.io/library/`,
+#   `docker.xuanyuan.me/library/`.
 
 services:
   # ========================
   # PostgreSQL Database
   # ========================
   postgres:
-    image: postgres:16-alpine
+    image: ${IMAGE_PREFIX:-}postgres:16-alpine
     container_name: quantdinger-db
     restart: unless-stopped
     environment:
@@ -48,6 +53,8 @@ services:
     build:
       context: ./backend_api_python
       dockerfile: Dockerfile
+      args:
+        BASE_IMAGE: ${IMAGE_PREFIX:-}python:3.12-slim-bookworm
     container_name: quantdinger-backend
     restart: unless-stopped
     depends_on:
@@ -58,8 +65,8 @@ services:
     volumes:
       - backend_logs:/app/logs
       - backend_data:/app/data
-      # Mount .env for runtime config
-      - ./backend_api_python/.env:/app/.env:ro
+      # Mount .env for runtime config and admin-panel updates
+      - ./backend_api_python/.env:/app/.env
     environment:
       - PYTHON_API_HOST=0.0.0.0
       - PYTHON_API_PORT=5000
@@ -75,12 +82,14 @@ services:
       retries: 3
 
   # ========================
-  # Frontend (Nginx + Vue build from QuantDinger-Vue-src)
+  # Frontend (Nginx serving prebuilt dist)
   # ========================
   frontend:
     build:
       context: .
       dockerfile: frontend/Dockerfile
+      args:
+        RUNTIME_IMAGE: ${IMAGE_PREFIX:-}nginx:1.25-alpine
     container_name: quantdinger-frontend
     restart: unless-stopped
     ports: