feat: live последние события на Dashboard; retention, health, runbook

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/jobs/__init__.py

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+"""Фоновые задачи SAC (retention и др.)."""

backend/app/jobs/retention.py

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+"""CLI: python -m app.jobs.retention"""
+
+from __future__ import annotations
+
+import logging
+import sys
+
+from app.config import get_settings
+from app.database import SessionLocal
+from app.services.retention import purge_old_data
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
+logger = logging.getLogger("sac.retention")
+
+
+def main() -> int:
+    settings = get_settings()
+    db = SessionLocal()
+    try:
+        stats = purge_old_data(db, settings)
+        logger.info(
+            "retention done events_deleted=%s problems_deleted=%s",
+            stats["events_deleted"],
+            stats["problems_deleted"],
+        )
+        return 0
+    except Exception:
+        db.rollback()
+        logger.exception("retention failed")
+        return 1
+    finally:
+        db.close()
+
+
+if __name__ == "__main__":
+    sys.exit(main())