(bugfix) Preserve scheduled backup warning status

Update the scheduler to reflect the actual scheduled BackupRun status after
a run completes, so prune warnings are shown as schedule warnings instead
of being reported as successful schedule executions.

src/pobsync_backend/management/commands/run_pobsync_scheduler.py

@@ -10,7 +10,7 @@ from django.core.management.base import BaseCommand
 from django.db import transaction
 from django.utils import timezone
 
-from pobsync_backend.models import ScheduleConfig
+from pobsync_backend.models import BackupRun, ScheduleConfig
 from pobsync_backend.scheduler import due_key, is_due
 
 
@@ -52,12 +52,13 @@ class Command(BaseCommand):
             if not is_due(schedule.cron_expr, now):
                 continue
 
+            schedule_started_at = timezone.now()
             with transaction.atomic():
                 locked = ScheduleConfig.objects.select_for_update().get(pk=schedule.pk)
                 if locked.last_due_key == current_due_key:
                     continue
                 locked.last_due_key = current_due_key
-                locked.last_started_at = timezone.now()
+                locked.last_started_at = schedule_started_at
                 locked.last_status = "running"
                 locked.save(update_fields=["last_due_key", "last_started_at", "last_status", "updated_at"])
 
@@ -72,6 +73,7 @@ class Command(BaseCommand):
                     prune_max_delete=schedule.prune_max_delete,
                     prune_protect_bases=schedule.prune_protect_bases,
                 )
+                status = _latest_scheduled_run_status(host_id=schedule.host_id, started_at=schedule_started_at) or status
             except Exception as exc:
                 status = "failed"
                 self.stderr.write(f"{schedule.host.host}: {type(exc).__name__}: {exc}")
@@ -83,3 +85,16 @@ class Command(BaseCommand):
             ran += 1
 
         return ran
+
+
+def _latest_scheduled_run_status(*, host_id: int, started_at) -> str | None:
+    run = (
+        BackupRun.objects.filter(
+            host_id=host_id,
+            run_type=BackupRun.RunType.SCHEDULED,
+            created_at__gte=started_at,
+        )
+        .order_by("-created_at", "-id")
+        .first()
+    )
+    return run.status if run is not None else None

src/pobsync_backend/tests/test_scheduler.py

@@ -8,7 +8,7 @@ from zoneinfo import ZoneInfo
 from django.test import SimpleTestCase, TestCase
 
 from pobsync_backend.management.commands.run_pobsync_scheduler import Command
-from pobsync_backend.models import HostConfig, ScheduleConfig
+from pobsync_backend.models import BackupRun, HostConfig, ScheduleConfig
 from pobsync_backend.scheduler import due_key, is_due, next_due_after
 
 
@@ -64,3 +64,30 @@ class SchedulerCommandTests(TestCase):
         self.assertEqual(call.call_count, 1)
         schedule = ScheduleConfig.objects.get(host=host)
         self.assertEqual(schedule.last_status, "success")
+
+    def test_run_due_records_warning_status_from_scheduled_backup_run(self) -> None:
+        host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
+        ScheduleConfig.objects.create(host=host, cron_expr="* * * * *", prune=True, prune_max_delete=1)
+
+        def create_warning_run(*args, **kwargs) -> None:
+            BackupRun.objects.create(
+                host=host,
+                run_type=BackupRun.RunType.SCHEDULED,
+                status=BackupRun.Status.WARNING,
+                result={
+                    "ok": True,
+                    "prune": {
+                        "ok": False,
+                        "type": "ConfigError",
+                        "error": "Refusing to delete 2 snapshots (exceeds --max-delete=1)",
+                    },
+                },
+            )
+
+        command = Command()
+        with patch("pobsync_backend.management.commands.run_pobsync_scheduler.call_command", side_effect=create_warning_run):
+            count = command._run_due(prefix=Path("/opt/pobsync"), dry_run=False)
+
+        self.assertEqual(count, 1)
+        schedule = ScheduleConfig.objects.get(host=host)
+        self.assertEqual(schedule.last_status, "warning")