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>

agent/runner.go

@@ -120,6 +120,8 @@ func Run(ctx context.Context, p *bootstate.Params) error {
 // (the orchestrator persists it as an artifact). Every other stage
 // returns a tests.Outcome which postResult marshals generically.
 func runStage(ctx context.Context, stage string, claim *ClaimResponse, fwd *logForwarder, c *Client, ovr overrideFlags) stageOutcome {
+	fwd.SetStage(stage)
+	defer fwd.ClearStage()
 	deps := newDeps(ctx, c, fwd, ovr, claim)
 	switch stage {
 	case "Inventory":
@@ -436,6 +438,7 @@ type logForwarder struct {
 	c      *Client
 	mu     sync.Mutex
 	buf    []LogLine
+	stage  string // set via SetStage; empties via ClearStage
 	wg     sync.WaitGroup
 	cancel context.CancelFunc
 }
@@ -467,7 +470,7 @@ func (f *logForwarder) push(level, text string) {
 	stamp := time.Now().UTC().Format(time.RFC3339Nano)
 	log.Printf("[%s] %s", level, text)
 	f.mu.Lock()
-	f.buf = append(f.buf, LogLine{TS: stamp, Level: level, Text: text})
+	f.buf = append(f.buf, LogLine{TS: stamp, Level: level, Stage: f.stage, Text: text})
 	f.mu.Unlock()
 }
 
@@ -475,6 +478,23 @@ func (f *logForwarder) info(s string)  { f.push("info", s) }
 func (f *logForwarder) warn(s string)  { f.push("warn", s) }
 func (f *logForwarder) error(s string) { f.push("error", s) }
 
+// SetStage tags subsequent log lines with a stage name so the orchestrator
+// can fan them out on a per-stage SSE event. Safe to call concurrently
+// with push — we take the same mutex.
+func (f *logForwarder) SetStage(stage string) {
+	f.mu.Lock()
+	f.stage = stage
+	f.mu.Unlock()
+}
+
+// ClearStage reverts to untagged (framing-level) logging. Defer this
+// on entry to runStage so hold/override paths don't leak stage context.
+func (f *logForwarder) ClearStage() {
+	f.mu.Lock()
+	f.stage = ""
+	f.mu.Unlock()
+}
+
 func (f *logForwarder) flush() {
 	f.mu.Lock()
 	if len(f.buf) == 0 {