feat(admin): implement full day-by-day schedule editor with live preview

## Features

### Admin Schedule Page (`packages/app/src/pages/admin/schedule.vue`)
- Interactive date-based slot editor for managing daily schedules
- Real-time slot editing: start/end times, capacity adjustments
- Slot deletion with conflict warnings when bookings exist
- Add new slots with modal dialog
- Live booking status display (booked count, people names)
- Publish/Save changes with sync feedback
- Revert unsaved changes with confirmation
- Skeleton loading states and empty state handling
- Responsive design with optimized mobile UX

### Backend Enhancements
- **New DTO** (`PublishDaySlotsDto`): Structured slot publishing with validation
  - Date string validation
  - Slot array with existing slot IDs for updates
  - Time and capacity validation per slot

- **Schedule Preview API** (`getSchedulePreview`):
  - Check for existing published slots
  - Fallback to active WeekTemplates for unpublished dates
  - Unified response format with isPublished flag

- **Publish Slots API** (`publishDaySlots`):
  - Atomic transaction for consistency
  - Update existing slots with new times/capacity
  - Create new slots from template data
  - Delete unpublished slots or set to CLOSED if bookings exist
  - Prevent capacity reduction below existing bookings
  - Returns all published slots for feedback

### State Management
- Enhanced admin store with schedule state
- Support for pending/unsaved slot changes
- Optimistic UI updates with server sync

### Documentation
- Comprehensive scheduling system architecture docs
- Quick reference for admin workflows
- Flow diagrams and state transitions
- Implementation guide for future maintenance

## Breaking Changes
None

## Testing Recommendations
- Create slots for future dates via schedule editor
- Verify booking prevention for locked/full slots
- Test capacity adjustments with existing bookings
- Confirm template-based schedule generation
- Verify transaction rollback on publish failures

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

packages/app/src/pages/admin/week-template.vue

@@ -163,9 +163,9 @@ const dayOptions = [1, 2, 3, 4, 5, 6, 7].map((d) => ({ label: WEEKDAY_LABELS[d],
 
 const form = ref({
   dayIdx: 0,
-  startTime: '09:00',
-  endTime: '10:00',
-  capacityStr: '10',
+  startTime: '08:00',
+  endTime: '09:00',
+  capacityStr: '1',
 })
 
 const grouped = computed(() => {
@@ -180,11 +180,38 @@ const grouped = computed(() => {
   )
 })
 
+/** 生成默认模板：周一到周日，8:00-22:00 每小时一个时段 */
+function generateDefaultTemplates(): LocalTemplate[] {
+  const defaults: LocalTemplate[] = []
+  for (let day = 1; day <= 7; day++) {
+    for (let hour = 8; hour < 22; hour++) {
+      const start = String(hour).padStart(2, '0') + ':00'
+      const end = String(hour + 1).padStart(2, '0') + ':00'
+      defaults.push({
+        _key: `default-${day}-${start}`,
+        dayOfWeek: day,
+        startTime: start,
+        endTime: end,
+        capacity: 1,
+        isActive: true,
+      })
+    }
+  }
+  return defaults
+}
+
 async function fetchTemplates() {
   loading.value = true
   try {
-    templates.value = await adminStore.fetchWeekTemplates()
-    isDirty.value = false
+    const data = await adminStore.fetchWeekTemplates()
+    if (data.length === 0) {
+      // No templates yet — pre-fill with defaults
+      templates.value = generateDefaultTemplates()
+      isDirty.value = true
+    } else {
+      templates.value = data
+      isDirty.value = false
+    }
   } catch {
     uni.showToast({ title: '加载失败', icon: 'none' })
   } finally {
@@ -194,7 +221,7 @@ async function fetchTemplates() {
 
 function openAdd() {
   editTarget.value = null
-  form.value = { dayIdx: 0, startTime: '09:00', endTime: '10:00', capacityStr: '10' }
+  form.value = { dayIdx: 0, startTime: '08:00', endTime: '09:00', capacityStr: '1' }
   showModal.value = true
 }