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/deploy/caddy.conf

@@ -1,9 +0,0 @@
-0.0.0.0:80 {
-  gzip
-  root /usr/share/nginx/html
-
-  rewrite {
-    r .*
-    to {path} /
-  }
-}

quantdinger_vue/deploy/nginx-docker.conf

@@ -1,43 +0,0 @@
-server {
-    listen 80;
-    server_name localhost;
-    root /usr/share/nginx/html;
-    index index.html;
-
-    # Gzip compression
-    gzip on;
-    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
-    gzip_min_length 1000;
-
-    # Static asset caching
-    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
-        expires 1y;
-        add_header Cache-Control "public, immutable";
-    }
-
-    # API proxy to backend
-    location /api/ {
-        proxy_pass http://backend:5000/api/;
-        proxy_http_version 1.1;
-        proxy_set_header Upgrade $http_upgrade;
-        proxy_set_header Connection 'upgrade';
-        proxy_set_header Host $host;
-        proxy_set_header X-Real-IP $remote_addr;
-        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-        proxy_set_header X-Forwarded-Proto $scheme;
-        proxy_cache_bypass $http_upgrade;
-        proxy_read_timeout 300s;
-        proxy_connect_timeout 75s;
-    }
-
-    # SPA routing support
-    location / {
-        try_files $uri $uri/ /index.html;
-    }
-
-    # Health check
-    location /health {
-        return 200 'OK';
-        add_header Content-Type text/plain;
-    }
-}

quantdinger_vue/deploy/nginx.conf

@@ -1,24 +0,0 @@
-server {
-    listen 80;
-    server_name  _;
-    # gzip config
-    gzip on;
-    gzip_min_length 1k;
-    gzip_comp_level 6;
-    gzip_types text/plain text/css text/javascript application/json application/javascript application/x-javascript application/xml;
-    gzip_vary on;
-    gzip_disable "MSIE [1-6]\.";
-
-    root /usr/share/nginx/html;
-    include /etc/nginx/mime.types;
-
-    location / {
-        try_files $uri $uri/ /index.html;
-    }
-
-#    location /api {
-#        proxy_pass https://preview.pro.antdv.com/api;
-#        proxy_set_header   X-Forwarded-Proto $scheme;
-#        proxy_set_header   X-Real-IP         $remote_addr;
-#    }
-}