Back up several stacks, or all of them, from one schedule (0.65.0)

A schedule covered exactly one stack, so backing up a host meant one
schedule per stack, each edited separately, and new stacks were only
backed up once someone remembered to add a schedule.

A schedule now takes a list of stacks, or all_stacks, which includes
stacks added later. They are backed up one after another, each with its
own file, upload, retention and status, so one failing stack does not
cost the others their backup:

- stack_status records each stack's result; last_status summarises
  ("error: 2 of 5 stacks - a: ...; c: ...") and one notification per run
  names the stacks with a problem. The dashboard names them too and shows
  an incomplete backup as a warning rather than an error.
- A busy stack (deploy, update) is retried after the others, up to three
  times two minutes apart, replacing the 10-minute postponement of the
  whole schedule.
- Run now starts the run in the background (202) instead of holding the
  request, which a multi-stack run would outlast; the list reports
  running and polls, and the row toasts the outcome. A schedule never
  runs twice at once.
- Settings: "All stacks" or a checklist with select all/none; stacks can
  be changed when editing; deleted stacks stay listed to be unticked.

Schedules from before keep working without a data migration: stack_ids,
all_stacks and stack_status are added with defaults on startup and a row
with only stack_id reads as that one stack. The API still accepts
stack_id and reports it for single-stack schedules.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/services/dashboard_service.py

@@ -15,7 +15,7 @@ from datetime import datetime, timedelta, timezone
 from sqlmodel import Session, select
 
 from docker_client import DockerError, get_client, safe_call
-from models.backup_schedule import BackupSchedule
+from models.backup_schedule import BackupSchedule, describe_stacks, status_of
 from services import compose_service, update_service
 
 COMPOSE_LABEL = compose_service.COMPOSE_LABEL
@@ -191,13 +191,20 @@ def _backup_attention(session: Session) -> list[dict]:
     for sch in session.exec(select(BackupSchedule).where(BackupSchedule.enabled == True)).all():  # noqa: E712
         host = "local"
         status = (sch.last_status or "").lower()
+        # Name the stacks that actually had a problem, not the whole schedule.
+        failing = sorted(
+            sid for sid, entry in status_of(sch).items()
+            if str((entry or {}).get("status", "")) != "ok"
+        )
+        what = ", ".join(failing) if failing else describe_stacks(sch)
         if status and not status.startswith("ok"):
-            items.append(_attn("error", "backup_failed", host,
-                               f"Backup of {sch.stack_id} failed", sch.last_status or "",
-                               "/settings"))
+            incomplete = status.startswith("warning")
+            items.append(_attn("warn" if incomplete else "error", "backup_failed", host,
+                               f"Backup of {what} {'is incomplete' if incomplete else 'failed'}",
+                               sch.last_status or "", "/settings"))
         elif sch.next_run and _aware(sch.next_run) < now - timedelta(hours=1):
             items.append(_attn("warn", "backup_overdue", host,
-                               f"Backup of {sch.stack_id} is overdue",
+                               f"Backup of {describe_stacks(sch)} is overdue",
                                "Scheduled run did not happen.", "/settings"))
     return items