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/webui/tasks.go

@@ -53,6 +53,7 @@ var taskNames = map[string]string{
 	"memory-stress":          "Memory Burn-in",
 	"sat-stress":             "SAT Stress (stressapptest)",
 	"platform-stress":        "Platform Thermal Cycling",
+	"fan":                    "Fan Ceiling Check (CPU+GPU load)",
 	"audit":                  "Audit",
 	"support-bundle":         "Support Bundle",
 	"install":                "Install to Disk",
@@ -196,7 +197,7 @@ func taskMayLeaveOrphanWorkers(target string) bool {
 	switch strings.TrimSpace(strings.ToLower(target)) {
 	case "nvidia", "nvidia-targeted-stress", "nvidia-targeted-power", "nvidia-pulse",
 		"nvidia-bandwidth", "nvidia-stress", "nvidia-compute", "nvidia-bench-perf",
-		"memory", "memory-stress", "cpu", "sat-stress", "platform-stress":
+		"memory", "memory-stress", "cpu", "sat-stress", "platform-stress", "fan":
 		return true
 	default:
 		return false
@@ -343,6 +344,9 @@ var (
 	runSATStressPackCtx = func(a *app.App, ctx context.Context, baseDir string, durationSec int, logFunc func(string)) (string, error) {
 		return a.RunSATStressPackCtx(ctx, baseDir, durationSec, logFunc)
 	}
+	runFanCheckPackCtx = func(a *app.App, ctx context.Context, baseDir string, opts platform.FanCheckOptions, logFunc func(string)) (string, error) {
+		return a.RunFanCheckCtx(ctx, baseDir, opts, logFunc)
+	}
 	buildSupportBundle = app.BuildSupportBundle
 	installCommand     = func(ctx context.Context, device string, logPath string) *exec.Cmd {
 		return exec.CommandContext(ctx, "bee-install", device, logPath)