v2.2.1: frontend closed-source + Docker one-click deploy

- Remove frontend source code (now in private repo)
- Add pre-built frontend/dist/ with Nginx serving
- Simplify docker-compose.yml (no Node.js build needed)
- Update README with docs index and Docker deploy guide
- Add admin order list and AI analysis stats tabs
- Add quick trade API routes
- Clean up redundant files (package-lock.json, yarn.lock, .iml)
- Add GitHub Actions workflow for frontend update automation

quantdinger_vue/Dockerfile

@@ -1,32 +0,0 @@
-# QuantDinger Frontend Dockerfile
-# Stage 1: Build
-FROM node:18-alpine as builder
-
-WORKDIR /app
-
-# Copy package files
-COPY package*.json ./
-
-# Install dependencies (prefer npm)
-RUN npm install --legacy-peer-deps
-
-# Copy source code
-COPY . .
-
-# Build production version
-RUN npm run build
-
-# Stage 2: Production image (using nginx)
-# Use specific version to avoid mirror registry issues
-FROM nginx:1.25-alpine
-
-# Copy build artifacts
-COPY --from=builder /app/dist /usr/share/nginx/html
-
-# Copy nginx configuration
-COPY deploy/nginx-docker.conf /etc/nginx/conf.d/default.conf
-
-# Expose port
-EXPOSE 80
-
-CMD ["nginx", "-g", "daemon off;"]