Host detail v2: full pipeline + per-stage logs + WoL diagnostics

Pipeline now always renders all 13 nodes (3 pre-stage + 9 stage +
Completed), synthesising ghosts from run state when stage rows
aren't seeded yet. Makes a WaitingWoL host show the full timeline
ahead of it instead of just 4 dots.

Agent tags each log line with its stage; logs.Hub fans out to both
log-{runID} and log-{runID}-{stage} SSE events so the detail page
can show per-stage tabs with a pure-CSS radio-sibling switch. Flat
run log prepends [stage] so grep still works.

Dispatcher writes picked/sent-WoL/heartbeat lines into the per-run
log — the operator opens the detail page, sees WaitingWoL stuck,
and reads exactly what the dispatcher did and why nothing's
progressing, instead of having to tail journalctl on the LXC.

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

internal/api/host_detail_test.go

@@ -121,6 +121,53 @@ func TestHostDetail_NeverRun(t *testing.T) {
 	}
 }
 
+// TestHostDetail_LogTabsRendered: when a run exists, the detail page
+// emits the log-tabs scaffold with one radio per stage + an "All" tab
+// checked by default. CSS sibling selectors drive visibility — no JS.
+func TestHostDetail_LogTabsRendered(t *testing.T) {
+	ui, hosts, runs := setupDetail(t)
+	ctx := context.Background()
+	id, err := hosts.Create(ctx, model.Host{
+		Name:             "tabs-host",
+		MAC:              "aa:bb:cc:dd:ee:40",
+		WoLBroadcastIP:   "10.0.0.255",
+		WoLPort:          9,
+		ExpectedSpecYAML: "memory:\n  total_gib: 16\n",
+	})
+	if err != nil {
+		t.Fatalf("create host: %v", err)
+	}
+	runID, err := runs.Create(ctx, id, "cafef00d")
+	if err != nil {
+		t.Fatalf("create run: %v", err)
+	}
+
+	rr := httptest.NewRecorder()
+	ui.HostDetail(rr, detailReq(id))
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status = %d", rr.Code)
+	}
+	body := rr.Body.String()
+
+	// All tab: the default-checked radio, plus its pane.
+	wantAllID := fmt.Sprintf(`id="log-tab-%d-all"`, runID)
+	if !strings.Contains(body, wantAllID) {
+		t.Fatalf("body missing All tab radio %s", wantAllID)
+	}
+	// Per-stage tabs: every entry in DefaultStageOrder must have its own
+	// radio + pane so tabs switch purely via sibling CSS.
+	for _, s := range store.DefaultStageOrder {
+		wantRadio := fmt.Sprintf(`id="log-tab-%d-%s"`, runID, s)
+		if !strings.Contains(body, wantRadio) {
+			t.Fatalf("body missing stage tab radio %s", wantRadio)
+		}
+		wantPane := fmt.Sprintf(`id="log-%d-%s"`, runID, s)
+		if !strings.Contains(body, wantPane) {
+			t.Fatalf("body missing stage pane %s", wantPane)
+		}
+	}
+}
+
 func TestHostDetail_UnknownID(t *testing.T) {
 	ui, _, _ := setupDetail(t)
 	rr := httptest.NewRecorder()