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

tests/integration/test_scheduler_api.py

@@ -1,6 +1,17 @@
 """调度器 API 集成测试 - 测试 /api/scheduler/* 所有接口"""
 import pytest
 
+from app.api.deps import get_settings_repo
+from app.repositories.settings_repo import SettingsRepository
+
+
+class FailingSettingsRepository(SettingsRepository):
+    """save 恒为 False，用于覆盖「设置保存失败」分支，非 MagicMock。"""
+
+    @staticmethod
+    async def save(db, settings):
+        return False
+
 
 class TestSchedulerAPI:
     """测试调度器相关 API"""
@@ -93,18 +104,17 @@ class TestSchedulerAPI:
         assert job is not None
 
     @pytest.mark.asyncio
-    async def test_start_scheduler_db_save_failure(self, client, monkeypatch):
+    async def test_start_scheduler_db_save_failure(self, client, app):
         """测试启动调度器时数据库保存失败应返回 running=False"""
-        from app.repositories.settings_repo import SettingsRepository
-
         # lifespan 启动时调度器可能已自动启动，先停止它
         await client.post("/api/scheduler/stop")
 
-        async def mock_save(*args, **kwargs):
-            return False
+        app.dependency_overrides[get_settings_repo] = lambda: FailingSettingsRepository()
+        try:
+            response = await client.post("/api/scheduler/start")
+        finally:
+            app.dependency_overrides.pop(get_settings_repo, None)
 
-        monkeypatch.setattr(SettingsRepository, "save", mock_save)
-        response = await client.post("/api/scheduler/start")
         assert response.status_code == 200
         data = response.json()
         assert data["code"] == 200