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/repositories/settings_repo.py

@@ -6,13 +6,12 @@ from app.core.log import logger
 
 
 DEFAULT_SETTINGS = {
-    "crawl_timeout": 30,
-    "validation_timeout": 10,
-    "max_retries": 3,
-    "default_concurrency": 50,
+    "validation_timeout": 6,
+    "default_concurrency": 120,
     "min_proxy_score": 0,
     "proxy_expiry_days": 7,
     "auto_validate": True,
+    "auto_validate_after_crawl": False,
     "validate_interval_minutes": 30,
     "validation_targets": [
         "http://httpbin.org/ip",
@@ -50,6 +49,8 @@ class SettingsRepository:
                         settings[key] = value
         except Exception as e:
             logger.error(f"get_all settings failed: {e}")
+        # 已废弃：爬取限时改为每插件 crawl_timeout_seconds，不再存全局项
+        settings.pop("crawl_timeout", None)
         return settings
 
     @staticmethod