ui: GitHub-Actions-style detail page, sub-steps, mini-tile run-view

Reshapes the detail page into a run-view: hybrid horizontal pipeline
+ expanded active-step pane with sub-steps, a per-step log pane with
line-numbered permalinks and client-side search, and a runs-history
sidebar that navigates via ?run=N. Default step is server-picked
(running → failed → Reporting) so the operator lands on the thing
that's moving.

Adds a sub_steps table + SSE topic (substep-{run}-{stage}-{ordinal})
so per-disk and per-pass work (SMART, CPUStress CPU/RAM, Storage,
GPU) is visible in the UI instead of buried in stage summary JSON.
Agent emits sub-step reports from existing per-iteration loops.

Dashboard tiles become a mini run-view with a 9-dot step strip so
the operator reads run health across the whole grid at a glance.
Register page gets the same card shell + button styling.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

cmd/vetting/main.go

@@ -56,6 +56,7 @@ func main() {
 	hostStore := &store.Hosts{DB: conn}
 	runStore := &store.Runs{DB: conn}
 	stageStore := &store.Stages{DB: conn}
+	subStepStore := &store.SubSteps{DB: conn}
 	artifactStore := &store.Artifacts{DB: conn}
 	specDiffStore := &store.SpecDiffs{DB: conn}
 	measurementStore := &store.Measurements{DB: conn}
@@ -77,6 +78,7 @@ func main() {
 
 	tiles := &api.TileEnricher{
 		Runs:      runStore,
+		Stages:    stageStore,
 		Artifacts: artifactStore,
 		SpecDiffs: specDiffStore,
 	}
@@ -90,6 +92,7 @@ func main() {
 		return templates.RenderTileString(tiles.Build(ctx, host, latest))
 	}
 	orchestrator.PipelineRenderer = templates.RenderPipelineString
+	orchestrator.SubStepRenderer = templates.RenderSubStepRowString
 
 	notifyReg, err := notify.BuildRegistry(cfg.Notifiers, cfg.Routes)
 	if err != nil {
@@ -100,6 +103,7 @@ func main() {
 		Hosts:     hostStore,
 		Runs:      runStore,
 		Stages:    stageStore,
+		SubSteps:  subStepStore,
 		SpecDiffs: specDiffStore,
 		Artifacts: artifactStore,
 		EventHub:  hub,
@@ -114,7 +118,10 @@ func main() {
 	// reload-rendered page byte-for-byte, then hands each region to
 	// its Render*String helper.
 	orchestrator.HostDetailRenderer = func(ctx context.Context, hostID int64) (orchestrator.HostDetailFragments, bool) {
-		d, err := ui.LoadHostDetailData(ctx, hostID)
+		// Orchestrator-side publishes always reference the latest run —
+		// SSE topics are keyed by runID, so a stale ?run=N bookmark
+		// doesn't affect what the server pushes.
+		d, err := ui.LoadHostDetailData(ctx, hostID, 0)
 		if err != nil {
 			return orchestrator.HostDetailFragments{}, false
 		}
@@ -134,6 +141,7 @@ func main() {
 		Hosts:           hostStore,
 		Runs:            runStore,
 		Stages:          stageStore,
+		SubSteps:        subStepStore,
 		Artifacts:       artifactStore,
 		SpecDiffs:       specDiffStore,
 		Measurements:    measurementStore,