(bugfix) Reconcile failed dry-runs from rsync terminal logs

Classify rsync failures in run results so transport issues such as exit
255 and broken pipes show clearer diagnostic hints.

Teach the worker to reconcile running dry-runs when their log already
contains a terminal rsync error, and to fail stale dry-runs after their
timeout window. This prevents failed rsync processes from leaving runs
stuck in the running state indefinitely.

src/pobsync_backend/management/commands/run_pobsync_worker.py

@@ -8,7 +8,7 @@ from django.conf import settings
 from django.core.management.base import BaseCommand
 
 from pobsync.paths import PobsyncPaths
-from pobsync_backend.backup_runner import claim_next_queued_run, execute_backup_run, requested_options
+from pobsync_backend.backup_runner import claim_next_queued_run, execute_backup_run, reconcile_running_runs, requested_options
 
 
 class Command(BaseCommand):
@@ -33,9 +33,10 @@ class Command(BaseCommand):
             time.sleep(max(1, int(options["interval"])))
 
     def _run_once(self, *, prefix: Path) -> int:
+        reconciled = reconcile_running_runs()
         run = claim_next_queued_run()
         if run is None:
-            return 0
+            return reconciled
 
         options = requested_options(run)
         try:
@@ -49,4 +50,4 @@ class Command(BaseCommand):
             )
         except Exception as exc:
             self.stderr.write(f"{run.host.host}: {type(exc).__name__}: {exc}")
-        return 1
+        return reconciled + 1