fix(tui): restore story list on completion screen

When EventStoryStarted was removed during the prd.json cleanup, the code
that set currentStoryID and currentStoryStart was lost. Without these,
finalizeStoryTiming() always returned early, leaving storyTimings empty
and the completion screen without its story list.

Attach the current storyID to EventIterationStart events from the loop,
and start tracking story timing in the TUI when the story changes.

Author: MiniCodeMonkey

internal/loop/loop.go

@@ -191,10 +191,14 @@ func (l *Loop) Run(ctx context.Context) error {
 			l.mu.Unlock()
 		}
 
-		// Send iteration start event
+		// Send iteration start event with current story ID
+		l.mu.Lock()
+		iterStoryID := l.currentStoryID
+		l.mu.Unlock()
 		l.events <- Event{
 			Type:      EventIterationStart,
 			Iteration: currentIter,
+			StoryID:   iterStoryID,
 		}
 
 		// Run a single iteration with retry logic

internal/tui/app.go

@@ -927,6 +927,12 @@ func (a App) handleLoopEvent(prdName string, event loop.Event) (tea.Model, tea.C
 	case loop.EventIterationStart:
 		if isCurrentPRD {
 			a.lastActivity = "Starting iteration..."
+			// Start tracking story timing if this is a new story
+			if event.StoryID != "" && event.StoryID != a.currentStoryID {
+				a.finalizeStoryTiming()
+				a.currentStoryID = event.StoryID
+				a.currentStoryStart = time.Now()
+			}
 		}
 	case loop.EventAssistantText:
 		if isCurrentPRD {