fix: sync nav timer with timer mode and checklist mode (#79)

Nav RestTimer now shows set elapsed when a set timer is active,
matching what TimerMode displays. Session page passes startedAt
to the store so session elapsed works in checklist mode too.
Store init() preserves existing rest timers.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyldmo

src/features/workouts/WorkoutSessionPage.tsx

@@ -99,11 +99,11 @@ export function WorkoutSessionPage() {
 		{ enabled: !!effectiveSessionId }
 	)
 
-	// Signal rest timer that a session is active (sessionId only — elapsed activates from TimerMode)
+	// Signal rest timer that a session is active
 	const isCompleteSession = !!sessionQuery.data?.completedAt
 	useEffect(() => {
 		if (sessionQuery.data && !isCompleteSession) {
-			storeSetSession({ id: sessionQuery.data.id })
+			storeSetSession({ id: sessionQuery.data.id, startedAt: sessionQuery.data.startedAt })
 		} else if (isCompleteSession) {
 			storeReset()
 		}

src/features/workouts/components/RestTimer.tsx

@@ -9,10 +9,14 @@ export const RestTimer: FC = () => {
 	const sessionId = useWorkoutSessionStore(s => s.sessionId)
 	const sessionStartedAt = useWorkoutSessionStore(s => s.sessionStartedAt)
 	const rest = useWorkoutSessionStore(s => s.rest)
+	const setTimer = useWorkoutSessionStore(s => s.active?.setTimer)
 	const dismissRest = useWorkoutSessionStore(s => s.dismissRest)
 	const navigate = useNavigate()
-	const isRunning = rest !== null
-	const elapsed = useElapsedTimer(!isRunning && sessionStartedAt ? sessionStartedAt : null)
+	const isResting = rest !== null
+	const setTimerActive = setTimer && !setTimer.isPaused ? setTimer.startedAt : null
+	const sessionElapsedTimestamp = isResting || setTimerActive ? null : sessionStartedAt
+	const elapsed = useElapsedTimer(sessionElapsedTimestamp)
+	const setElapsedMs = useElapsedTimer(isResting ? null : setTimerActive)
 	const remaining = -useElapsedTimer(rest?.endAt ?? null) / 1000
 
 	const goToTimer = () => {
@@ -52,6 +56,20 @@ export const RestTimer: FC = () => {
 		)
 	}
 
+	// Active set timer — show set elapsed (matches timer mode)
+	if (sessionId && setTimerActive) {
+		return (
+			<button
+				type="button"
+				className="flex items-center gap-1.5 rounded-sm border border-edge px-2 py-1 text-ink-faint hover:text-accent"
+				onClick={goToTimer}
+			>
+				<Dumbbell className="size-3.5" />
+				<span className="font-mono text-sm tabular-nums">{formatTimer(setElapsedMs / 1000)}</span>
+			</button>
+		)
+	}
+
 	// Session active with timer activated — show elapsed time
 	if (sessionId && sessionStartedAt) {
 		return (

src/features/workouts/store/useWorkoutSessionStore.ts

@@ -161,14 +161,17 @@ export const useWorkoutSessionStore = create<WorkoutSessionStore>((set, get) =>
 	},
 
 	init: (sessionId, startedAt, sets) => {
-		clearNotificationTimeout()
+		const existing = get()
+		// Preserve rest timer if one is running (e.g., started in checklist mode)
+		if (!existing.rest) clearNotificationTimeout()
 		const cursor = findNextPending(sets, 0, [])
 		set({
 			...INITIAL_STATE,
 			sessionId,
 			sessionStartedAt: startedAt,
 			queue: sets,
-			active: loadActive(sets, cursor)
+			active: loadActive(sets, cursor),
+			rest: existing.rest
 		})
 	},