feat: fpw plugins, validation/crawl perf, WS stats, test DB isolation

- Add Free_Proxy_Website-style fpw_* plugins and register them
- Per-plugin crawl timeout (crawl_timeout_seconds=120); remove global crawl_timeout setting
- Validator: fix connect vs total timeout on save; SOCKS session LRU cache; drop redundant semaphore
- Validation handler uses single DB connection; batch upsert after crawl; WorkerPool put_nowait
- Remove unused max_retries from settings API/UI; settings maintenance SQL + init_db cleanup of deprecated keys
- WebSocket dashboard stats; ProxyList pool_filter and API alignment
- POST /api/proxies/delete-one for IPv6-safe deletes; task poll stops on 404
- pytest uses PROXYPOOL_DB_PATH=db/proxies.test.sqlite so tests do not wipe production DB
- .gitignore: explicit proxies.test.sqlite patterns; fix plugin_service ValidationException import

Made-with: Cursor

app/plugins/proxyscrape.py

@@ -109,21 +109,5 @@ class ProxyScrapePlugin(BaseHTTPPlugin):
         if results:
             logger.info(f"ProxyScrape 总计获取 {len(results)} 个代理")
         else:
-            # Fallback：生成测试代理，确保在测试环境也能验证完整流程
-            logger.warning("ProxyScrape 所有真实源均不可用，生成测试代理用于架构验证")
-            results = self._generate_test_proxies()
+            logger.warning("ProxyScrape 所有真实源均不可用，返回空列表")
         return results
-
-    def _generate_test_proxies(self) -> List[ProxyRaw]:
-        """生成测试代理数据，覆盖全协议类型，用于验证插件系统"""
-        import random
-        test_proxies = []
-        protocols = ["http", "https", "socks4", "socks5"]
-        for protocol in protocols:
-            for _ in range(3):
-                # 生成随机公网格式 IP（仅用于测试流程）
-                ip = f"{random.randint(1, 223)}.{random.randint(0, 255)}.{random.randint(0, 255)}.{random.randint(1, 254)}"
-                port = random.randint(1024, 65535)
-                test_proxies.append(ProxyRaw(ip, port, protocol))
-        logger.info(f"生成 {len(test_proxies)} 个测试代理 HTTP/HTTPS/SOCKS4/SOCKS5 各 3 个")
-        return test_proxies