feat(plugins): Traefik problems first, UniFi/SNMP/fleet on shared shapes, audit names its entities, templates on tokens (#5126)

Traefik: routers are graded from their latest scrape (router_state: crit on
any real 5xx share, warn on p95 past the latency critical cutoff or a high
4xx share). Failing and slow routers lead as cards that say why; healthy
ones fold into one table that stays open or shut across polls. Proxy
counts are stat tiles; certificates are graded by Settings -> Thresholds
(tls_days).

UniFi: WAN health is a stat strip (latency graded by the thresholds),
devices carry status dots, event categories and firewall actions are
badges, the alarm count reuses .count-badge (renamed from .nav-count).
SNMP: each device wears a status badge and its readings are stat tiles.

Agent fleet: the table comes first, with a Status column (Reporting /
Silent / Never reported, by the host page's stale_after_seconds), silent
agents first, hosts linked, last seen as |ago.

Audit: entries name their entity (one query per type, steward/audit/
service.py) and link it; something deleted since keeps the name its entry
recorded and says "(deleted)".

Tokens: charts read colours through chart-colors.js (stewardColor resolves
a token to the rgb the browser computed; Chart.js defaults take the page's
text and border colours), so host, history, Traefik and SNMP charts drop
their hex. Template hex colours reach 0 (HEX_CEILING = 0), the last rgba
pills go, and heavy weights (600/700/bold, 60 of them) become 500, the
house pair being 400/500; a guard keeps templates there.

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

steward/templates/settings/plugins.html

@@ -22,7 +22,7 @@
   {% endif %}
   <div style="flex:1;min-width:0;">
     <div style="display:flex;align-items:baseline;gap:0.5rem;flex-wrap:wrap;">
-      <span style="font-weight:600;font-size:0.9rem;color:var(--text);">{{ plugin.get('name', plugin._dir) }}</span>
+      <span style="font-weight:500;font-size:0.9rem;color:var(--text);">{{ plugin.get('name', plugin._dir) }}</span>
       <span style="font-size:0.75rem;color:var(--text-muted);">v{{ plugin.get('version', '?') }}</span>
       {% if fail_reason %}
         <span style="font-size:0.72rem;padding:0.1em 0.45em;border-radius:3px;
@@ -109,7 +109,7 @@
             title="{{ orphan.reason or 'Configured but not installed' }}"></span>
       <div style="flex:1;min-width:0;">
         <div style="display:flex;align-items:baseline;gap:0.5rem;flex-wrap:wrap;">
-          <span style="font-weight:600;font-size:0.9rem;color:var(--text);">{{ orphan.name }}</span>
+          <span style="font-weight:500;font-size:0.9rem;color:var(--text);">{{ orphan.name }}</span>
           {% if orphan.reason %}
           <span style="font-size:0.72rem;padding:0.1em 0.45em;border-radius:3px;
                        background:color-mix(in srgb,var(--red) 15%,var(--bg));color:var(--red);">Failed to load</span>