feat: SAC daily reports from DB aggregation (notif-32)

- Aggregate report.daily.ssh/rdp from 24h ingest; job and systemd timer

- notify_daily_report bypasses NOTIFY_MIN_SEVERITY; ingest routes agent reports

- HTML templates, env SAC_DAILY_REPORT_*, docs and tests (56 cases)

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

backend/app/services/notify_dispatch.py

@@ -47,3 +47,11 @@ def notify_problem(problem: Problem, event: Event | None = None, *, db: Session
     if not should_notify_problem(problem, db):
         return
     _dispatch_problem_channels(problem, event, db=db, policy=policy)
+
+
+def notify_daily_report(event: Event, *, db: Session | None = None) -> None:
+    """Оповещение по суточному отчёту (severity=info, вне порога policy)."""
+    policy = get_effective_notification_policy(db)
+    if not should_notify_event(event, db):
+        return
+    _dispatch_event_channels(event, db=db, policy=policy)