feat(dashboard): a curated default layout, merged duplicate widgets, a labelled Overview (#5213)

- New installs start from widgets.RECOMMENDED, packed row by row for the
  enabled plugins; the edit drawer can reset a dashboard to it.
- Host Agent — Resources folds into Hosts — Overview (which gains load 1m),
  UniFi — Devices into UniFi — Overview; migration 0032 moves existing
  dashboards onto the survivors.
- The Overview labels what it counts (hosts, monitors up/down/pending,
  alerts firing) and lists firing alerts and down monitors with since-times.
- Uptime polls every 5 minutes (poll_seconds) instead of every cycle.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

steward/status/routes.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 from quart import Blueprint, current_app, render_template, request
 from sqlalchemy import func, select
 
-from steward.alerts.service import active_alerts
+from steward.alerts.service import active_alerts, alert_label
 from steward.auth.middleware import require_role
 from steward.core.status import collect_status, sparkline_svg
 from steward.models.hosts import Host
@@ -53,10 +53,23 @@ async def widget():
         entries = await collect_status(db)
         total_hosts = (await db.execute(
             select(func.count()).select_from(Host))).scalar()
+        alerts = await active_alerts(db)
     up, down, pending = _summarize(entries)
     return await render_template(
         "status/widget.html",
         entries=entries, up=up, down=down, pending=pending,
-        total_hosts=total_hosts,
+        total_hosts=total_hosts, alerts=overview_alerts(alerts),
         widget_id=request.args.get("wid", "0"),
     )
+
+
+def overview_alerts(alerts) -> list[dict]:
+    """The Overview's alert lines: breaching or silent first, then those
+    someone has taken; each {rule, label, since}."""
+    order = {"firing": 0, "no_data": 1, "pending": 2, "acknowledged": 3}
+    rows = []
+    for state, rule in alerts:
+        label = alert_label(state)
+        since = state.no_data_since if label == "no_data" else state.last_transition_at
+        rows.append({"rule": rule, "label": label, "since": since})
+    return sorted(rows, key=lambda r: order.get(r["label"], 9))