feat(dashboard): Hosts widget worst first, load against cores, one home per fact (#5251)

The Hosts — Overview widget opens with a verdict ("VDNT-Util01: CPU high."
or "All 3 hosts healthy."), then one row per host under one header: CPU,
memory, disk / and load. Rows sort by host_glance: a down monitor, a
reading past critical, a quiet agent, a warning, then the healthy. Load
reads "16.8 / 8 cores", graded per core as Settings → Thresholds intends
(cores counted from the per-core CPU sub-resources, as on the host page).
A quiet agent's last figures are shown uncoloured, with when it last reported.

Ping and 24h uptime are gone from this widget: they belong to Monitors. So
are the unlabelled CPU sparkline and the 30-day uptime query it no longer
needs.

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

steward/hosts/routes.py

@@ -27,21 +27,15 @@ def _ansible_source_names() -> list[str]:
 @hosts_bp.get("/overview/widget")
 @require_role(UserRole.viewer)
 async def overview_widget():
-    """Dashboard widget: unified per-host monitor + agent glance, linking to the hub."""
+    """Dashboard widget: each host's resources, worst first (#5251). Uptime and
+    latency belong to the Monitors widget, so this one doesn't read them."""
     async with current_app.db_sessionmaker() as db:
         hosts = (await db.execute(select(Host).order_by(Host.name))).scalars().all()
         host_status = await host_svc.host_status(db, [h.id for h in hosts])
-        uptime = await host_svc.compute_uptime(db)
-        host_names = [h.name for h in hosts]
         agent = await host_svc.agent_overview_by_host(
-            db, host_names, host_svc.agent_stale_after_seconds(current_app.config))
-        cpu_sparks = await host_svc.agent_cpu_sparks_by_host(db, host_names)
-
-    return await render_template(
-        "hosts/overview_widget.html",
-        hosts=hosts, host_status=host_status,
-        uptime=uptime, agent=agent, cpu_sparks=cpu_sparks,
-    )
+            db, [h.name for h in hosts], host_svc.agent_stale_after_seconds(current_app.config))
+    rows = host_svc.host_glance(hosts, host_status, agent, current_app.config.get("THRESHOLDS", {}))
+    return await render_template("hosts/overview_widget.html", rows=rows)
 
 
 @hosts_bp.get("/")