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/api/routes/settings.py

@@ -1,10 +1,13 @@
 """设置相关路由"""
+import asyncio
+
 from fastapi import APIRouter, Request, Depends
 from app.core.db import get_db
 from app.repositories.settings_repo import SettingsRepository
 from app.models.schemas import SettingsSchema
 from app.api.common import success_response
 from app.api.deps import get_settings_repo
+from app.core.config import settings as app_settings
 from app.core.exceptions import ProxyPoolException
 from app.core.log import logger
 
@@ -47,17 +50,21 @@ async def save_settings(
 
     # 热更新验证器超时和并发（下次验证时生效）
     if validator:
-        validator._init_timeout = request.validation_timeout
-        validator._init_connect_timeout = request.validation_timeout
+        vt = float(request.validation_timeout)
+        validator._init_timeout = vt
+        # 连接阶段单独收紧：勿与 total 等同，否则死代理会在 connect 上耗满整段超时
+        validator._init_connect_timeout = min(
+            float(app_settings.validator_connect_timeout), vt
+        )
         validator._init_max_concurrency = request.default_concurrency
         if request.validation_targets is not None:
             validator.update_test_urls(request.validation_targets)
         # 延迟关闭旧 session：让正在验证的代理继续使用旧 session，
         # 新请求会通过 _ensure_session() 自动创建使用新配置的 session
+        await validator.close_socks_sessions()
         old_session = validator._http_session
         validator._http_session = None
         validator._http_connector = None
-        validator._semaphore = None
         if old_session and not old_session.closed:
             asyncio.create_task(old_session.close())
         logger.info(f"Validator config updated: timeout={request.validation_timeout}, concurrency={request.default_concurrency}, targets={request.validation_targets}")