feat: 添加 Docker 部署支持和多 OCR 提供商架构

- 添加完整的 Docker 配置 (Dockerfile, docker-compose.yml)
- 修复前端硬编码端口 4000，改用相对路径 /api
- 实现多 OCR 提供商架构 (Tesseract.js/Baidu/RapidOCR)
- 修复 Docker 环境中图片上传路径问题
- 添加用户设置页面和 AI 分析服务
- 更新 Prisma schema 支持 AI 分析结果
- 添加部署文档和 OCR 配置指南

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/nginx.docker.conf

@@ -0,0 +1,41 @@
+server {
+    listen 80;
+    server_name localhost;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Gzip compression
+    gzip on;
+    gzip_vary on;
+    gzip_min_length 1024;
+    gzip_types text/plain text/css text/xml text/javascript application/x-javascript application/xml+rss application/javascript application/json;
+
+    # Security headers
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-XSS-Protection "1; mode=block" always;
+
+    # API proxy to backend
+    location /api {
+        proxy_pass http://backend:13057;
+        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;
+    }
+
+    # Static files with caching
+    location /assets/ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    # SPA fallback - all non-file routes go to index.html
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+}