feat(sat): fan ceiling check + topology fan tiles

Repurpose the previously-unwired RunFanStressTest into RunFanCheck, a
Load-tier SAT test that drives stressapptest (CPU+memory) and, when a GPU
is present, a GPU burn to 100% simultaneously, then watches every fan
until none has climbed for ~60s. The observed peak RPM per fan is the
"ceiling"; it is persisted through the existing fan-observation store.

MSI G4201 / AMI MegaRAC exposes no host-side fan force (every OEM IPMI
command returns 0xc1; Redfish Thermal is GET-only), so load-driven ramp
is the closest safe equivalent. See
bible-local/decisions/2026-09-04-fan-ceiling-check.md.

- platform.ResolveFanMaxRPM: per-fan max with fallback (persisted peak ->
  peer peak -> current RPM), resolved in platform, not the view.
- platform.ErrTestNotApplicable: no load source or no fan sensors ->
  task lands as cancelled ("not applicable"), never failed, so an
  engineer never sees a false red. executeTaskWithOptions maps the
  sentinel; finalizeTaskForResult honours a pre-set TaskCancelled.
- Verdict FAIL only for a fan at 0 RPM / IPMI cr-nr under load.
- /topo: one small spinning square per fan, sized by RPM / resolved max,
  clickable through to a new "fan" component-detail type; per-fan status
  recorded to the component-status DB from the fan SAT summary.
- Wiring: /api/sat/fan/run route, "fan" task target, Load-page card,
  stress-mode Run All.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019VHG21rgTUiR1G3qFHTVmN

audit/internal/app/component_status_db.go

@@ -318,6 +318,23 @@ func ApplySATResultToDB(db *ComponentStatusDB, target, archivePath string) {
 		db.Record("memory:all", source, dbStatus, detail)
 	case "cpu", "platform-stress":
 		db.Record("cpu:all", source, dbStatus, detail)
+	case "fan":
+		// Per-fan keys: summary emits "fan_<name>_status=OK|FAILED (...)".
+		for key, val := range kv {
+			name, ok := strings.CutPrefix(key, "fan_")
+			if !ok {
+				continue
+			}
+			name, ok = strings.CutSuffix(name, "_status")
+			if !ok || name == "" {
+				continue
+			}
+			upper := strings.ToUpper(strings.TrimSpace(val))
+			if i := strings.IndexByte(upper, ' '); i > 0 {
+				upper = upper[:i] // drop the "(reason)" suffix
+			}
+			db.Record("fan:"+name, source, satStatusToDBStatus(upper), target+" SAT: "+strings.TrimSpace(val))
+		}
 	case "storage":
 		// Try to record per-device if available in summary.
 		recordedAny := false