feat(ocr): 集成 PaddleOCR 服务并优化 OCR 系统

- 新增 PaddleOCR 本地高精度 OCR 服务支持，包括 Dockerfile、API 服务和 provider 实现
- 在 docker-compose 中集成 RapidOCR 和 PaddleOCR 服务，并配置健康检查
- 优化后端 API 路由前缀，移除 `/api` 以简化代理配置
- 更新 Nginx 配置以正确传递请求头和代理 WebSocket 连接
- 在前端设置页面添加 PaddleOCR 和 RapidOCR 的测试与配置选项
- 修复后端 Dockerfile 以支持 Python 原生模块构建
- 更新 OCR 设置指南，反映当前服务状态和部署方式
- 添加上传文件调试日志和权限设置

docker-compose.yml

@@ -26,12 +26,18 @@ services:
       DEEPSEEK_API_KEY: ${DEEPSEEK_API_KEY:-}
       UPLOAD_MAX_SIZE: ${UPLOAD_MAX_SIZE:-10485760}
       UPLOAD_ALLOWED_TYPES: ${UPLOAD_ALLOWED_TYPES:-image/jpeg,image/png,image/webp}
+      # OCR Services URLs
+      RAPIDOCR_API_URL: ${RAPIDOCR_API_URL:-http://rapidocr:9004}
+      PADDLEOCR_API_URL: ${PADDLEOCR_API_URL:-http://paddleocr:8866}
     volumes:
       # Persist database and uploads
       - backend-data:/app/data
       - backend-uploads:/app/uploads
     networks:
       - picanalysis-network
+    depends_on:
+      - rapidocr
+      - paddleocr
     healthcheck:
       test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:13057/api/health"]
       interval: 30s
@@ -39,6 +45,45 @@ services:
       retries: 3
       start_period: 40s
 
+  # ========================
+  # RapidOCR Service (本地快速 OCR)
+  # ========================
+  rapidocr:
+    image: volador/rapidocr:latest
+    container_name: picanalysis-rapidocr
+    restart: unless-stopped
+    ports:
+      - "13058:9004"
+    networks:
+      - picanalysis-network
+    healthcheck:
+      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:9004"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 20s
+
+  # ========================
+  # PaddleOCR Service (本地高精度 OCR - 使用官方预构建镜像)
+  # ========================
+  paddleocr:
+    image: 987846/paddleocr:latest
+    container_name: picanalysis-paddleocr
+    restart: unless-stopped
+    ports:
+      - "13059:8866"
+    environment:
+      # 修复 protobuf 兼容性问题
+      PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION: python
+    networks:
+      - picanalysis-network
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8866/"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 60s
+
   # ========================
   # Frontend Service
   # ========================