refactor(backend): optimize database safety, validator performance, and scheduler concurrency

- Fix SQL injection risks in proxy_repo and task_repo
- Atomic acquire_pending with UPDATE ... RETURNING
- Reuse aiohttp ClientSession in ValidatorService
- Replace polling with asyncio.Event in SchedulerService
- Optimize ValidationQueue.drain with asyncio.Condition
- Concurrent plugin crawling with asyncio.gather
- Unify ProxyRaw model import path
- Fix test baseline and remove tracked __pycache__ files

app/plugins/fate0.py

@@ -6,9 +6,10 @@ from app.core.log import logger
 
 
 class Fate0Plugin(BaseHTTPPlugin):
+    default_config = {"max_pages": 5}
     name = "fate0"
-    display_name = "Fate0聚合源"
-    description = "从 GitHub 持续更新的高质量代理聚合列表"
+    display_name = "Fate0聚合站"
+    description = "来自 GitHub 持续更新的高质量代理聚合列表"
 
     def __init__(self):
         super().__init__()
@@ -34,5 +35,5 @@ class Fate0Plugin(BaseHTTPPlugin):
                 except Exception:
                     continue
         if results:
-            logger.info(f"{self.display_name} 解析完成，获得 {len(results)} 个潜在代理")
+            logger.info(f"{self.display_name} 解析完成，获取 {len(results)} 个潜在代理")
         return results