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>

plugins/unifi/routes.py

@@ -324,33 +324,3 @@ async def widget_clients():
         snapshot=snapshot,
         widget_id=widget_id,
     )
-
-
-@unifi_bp.get("/widget/devices")
-@require_role(UserRole.viewer)
-async def widget_devices():
-    """HTMX dashboard widget: infrastructure devices with optional type filter."""
-    type_filter = request.args.get("type_filter", "all")
-    widget_id = request.args.get("wid", "0")
-
-    async with current_app.db_sessionmaker() as db:
-        result = await db.execute(
-            select(UnifiDevice).order_by(UnifiDevice.state.desc(), UnifiDevice.name)
-        )
-        all_devices = result.scalars().all()
-
-    if type_filter == "wireless":
-        devices = [d for d in all_devices if d.device_type == "uap"]
-    elif type_filter == "wired":
-        devices = [d for d in all_devices if d.device_type != "uap"]
-    elif type_filter == "offline":
-        devices = [d for d in all_devices if d.state != 1]
-    else:
-        devices = list(all_devices)
-
-    return await render_template(
-        "unifi/widget_devices.html",
-        devices=devices,
-        type_filter=type_filter,
-        widget_id=widget_id,
-    )