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>

internal/web/templates/substep_row.templ

@@ -0,0 +1,81 @@
+package templates
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"time"
+
+	"vetting/internal/model"
+)
+
+// subStepDuration formats a sub-step's elapsed time the same way
+// stageDuration does for pipeline nodes. Empty string when not started.
+func subStepDuration(ss model.SubStep) string {
+	if ss.StartedAt == nil {
+		return ""
+	}
+	end := time.Now()
+	if ss.CompletedAt != nil {
+		end = *ss.CompletedAt
+	}
+	d := end.Sub(*ss.StartedAt)
+	if d < 0 {
+		d = 0
+	}
+	switch {
+	case d < time.Second:
+		return fmt.Sprintf("%dms", int(d/time.Millisecond))
+	case d < 10*time.Second:
+		return fmt.Sprintf("%.1fs", d.Seconds())
+	case d < time.Minute:
+		return fmt.Sprintf("%ds", int(d/time.Second))
+	case d < time.Hour:
+		return fmt.Sprintf("%dm", int(d/time.Minute))
+	default:
+		return fmt.Sprintf("%dh", int(d/time.Hour))
+	}
+}
+
+// subStepMarker mirrors stageMarker — a single-char glyph used inside the
+// state badge. StageState values reused verbatim for sub-steps.
+func subStepMarker(s model.StageState) string {
+	switch s {
+	case model.StagePassed:
+		return "✓"
+	case model.StageFailed:
+		return "!"
+	case model.StageRunning:
+		return "●"
+	case model.StageSkipped:
+		return "–"
+	}
+	return ""
+}
+
+// SubStepRow renders one sub-step entry for the expanded-step pane. The
+// outer <div> carries the sse-swap target keyed by (runID, stage,
+// ordinal) so the orchestrator's PublishSubStepUpdate can swap just this
+// row without touching the rest of the stage panel. hx-swap="outerHTML"
+// keeps the attributes intact across repeat swaps.
+templ SubStepRow(ss model.SubStep) {
+	<div
+		id={ fmt.Sprintf("substep-%d-%s-%d", ss.RunID, ss.StageName, ss.Ordinal) }
+		class={ "substep", "substep-" + string(ss.State) }
+		sse-swap={ fmt.Sprintf("substep-%d-%s-%d", ss.RunID, ss.StageName, ss.Ordinal) }
+		hx-swap="outerHTML"
+	>
+		<span class={ "substep-badge", "substep-badge-" + string(ss.State) }>{ subStepMarker(ss.State) }</span>
+		<span class="substep-name">{ ss.Name }</span>
+		<span class="substep-duration">{ subStepDuration(ss) }</span>
+	</div>
+}
+
+// RenderSubStepRowString is the one-shot renderer the orchestrator
+// registers as SubStepRenderer so it can emit substep-* SSE payloads
+// without importing the templates package directly.
+func RenderSubStepRowString(ss model.SubStep) string {
+	var buf bytes.Buffer
+	_ = SubStepRow(ss).Render(context.Background(), &buf)
+	return buf.String()
+}