feat(time-tracking) : show real-time timer in browser tab title

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/layouts/default.vue

@@ -134,6 +134,28 @@ const currentProjectId = computed(() => {
 
 const timerStore = useTimerStore()
 
+const baseTitle = ref('Lesstime')
+
+useHead({
+    titleTemplate: (title) => {
+        baseTitle.value = title || 'Lesstime'
+        return title || 'Lesstime'
+    },
+})
+
+watch(
+    [() => timerStore.elapsedFormatted, () => timerStore.isRunning, () => timerStore.activeEntry?.title],
+    ([elapsed, running, label]) => {
+        if (import.meta.server) return
+        const base = baseTitle.value
+        if (running) {
+            document.title = label ? `${base} | ${elapsed} · ${label}` : `${base} | ${elapsed}`
+        } else {
+            document.title = base
+        }
+    },
+)
+
 onMounted(() => {
     timerStore.fetchActive()
 })