chore: 忽略离线部署包，提交安全加固、数据库初始化与文档

- .gitignore: 忽略 docker/offline 离线部署包（镜像/运行时等大文件）
- 安全加固: 新增 compute/api/security.py 及各端安全测试，补充 docs/security-hardening.md
- 数据库: 新增完整初始化 SQL 与 docs/database-config.md
- 数据转换与评测: 修复类型检查、增强校验并补充测试
- Docker 配置与环境变量更新

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

backend/app/main.py

@@ -5,7 +5,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.api.v1.router import api_router
-from app.core.config import get_settings
+from app.core.config import docs_kwargs, get_settings
 from app.core.logging import configure_logging, setup_request_logging
 from app.workers.compute_poller import run_compute_poller
 
@@ -14,7 +14,7 @@ def create_app() -> FastAPI:
     settings = get_settings()
     configure_logging(settings)
 
-    app = FastAPI(title=settings.app_name)
+    app = FastAPI(title=settings.app_name, **docs_kwargs(settings.enable_docs))
     app.add_middleware(
         CORSMiddleware,
         allow_origins=settings.cors_allow_origins,