fix(server): hide CLOSED rows from preview for legacy mini-program compatibility

The previous fix made publishDaySlots CLOSE rows instead of DELETE them.
That works correctly on the server, but the live mini-program still ships
the old schedule.vue which only knows about isPublished (no status
field). It would re-render the CLOSED rows with the '已发布' badge,
making it look like 'clear day' did nothing.

Hide CLOSED rows from getSchedulePreview so the legacy client shows
'当日暂无排课' for rest days — the same UX it had before this fix
shipped. All-CLOSED days return []; days with a mix return only the
non-CLOSED rows; days the cron hasn't touched still return the ghost
template.

The republished mini-program (with status-aware rendering) will see the
same [] for rest days, which is consistent. Tests: 4 new specs covering
all-OPEN / all-CLOSED / mixed / empty-day cases.

packages/server/src/time-slot/__tests__/time-slot.service.spec.ts

@@ -231,6 +231,69 @@ describe('TimeSlotService', () => {
     })
   })
 
+  // -------------------------------------------------------------------------
+  // getSchedulePreview
+  // -------------------------------------------------------------------------
+  describe('getSchedulePreview', () => {
+    const date = '2026-04-07'
+
+    it('returns OPEN/FULL rows with isPublished: true', async () => {
+      mockPrisma.timeSlot.findMany.mockResolvedValueOnce([
+        makeSlot({ id: 'slot-1', startTime: '09:00', endTime: '10:00', status: TimeSlotStatus.OPEN }),
+        makeSlot({ id: 'slot-2', startTime: '10:30', endTime: '11:30', status: TimeSlotStatus.FULL }),
+      ])
+
+      const result = await service.getSchedulePreview(date)
+
+      expect(result).toHaveLength(2)
+      expect(result.every((s) => s.isPublished === true)).toBe(true)
+    })
+
+    it('HIDES CLOSED rows so the legacy client does not render them as "已发布"', async () => {
+      // Simulates an admin "clear day" — DB now has 13 CLOSED rows.
+      mockPrisma.timeSlot.findMany.mockResolvedValueOnce(
+        Array.from({ length: 13 }, (_, i) =>
+          makeSlot({
+            id: `slot-${i}`,
+            startTime: `${String(8 + Math.floor(i / 2)).padStart(2, '0')}:${i % 2 === 0 ? '00' : '30'}`,
+            endTime: `${String(8 + Math.floor(i / 2)).padStart(2, '0')}:${i % 2 === 0 ? '30' : '30'}`,
+            status: TimeSlotStatus.CLOSED,
+          }),
+        ),
+      )
+
+      const result = await service.getSchedulePreview(date)
+
+      // Critical for online compatibility: the legacy client must see []
+      // so it shows "当日暂无排课", not 13 phantom "已发布" slots.
+      expect(result).toEqual([])
+    })
+
+    it('returns the OPEN subset and hides CLOSED when mixed', async () => {
+      mockPrisma.timeSlot.findMany.mockResolvedValueOnce([
+        makeSlot({ id: 'open-1', status: TimeSlotStatus.OPEN }),
+        makeSlot({ id: 'closed-1', status: TimeSlotStatus.CLOSED, startTime: '10:00', endTime: '11:00' }),
+        makeSlot({ id: 'open-2', status: TimeSlotStatus.OPEN, startTime: '10:30', endTime: '11:30' }),
+      ])
+
+      const result = await service.getSchedulePreview(date)
+
+      expect(result).toHaveLength(2)
+      expect(result.map((s) => s.id).sort()).toEqual(['open-1', 'open-2'])
+      expect(result.find((s) => s.id === 'closed-1')).toBeUndefined()
+    })
+
+    it('returns the ghost template when the day has no rows at all', async () => {
+      mockPrisma.timeSlot.findMany.mockResolvedValueOnce([])
+
+      const result = await service.getSchedulePreview(date)
+
+      // Ghost = isPublished false, id null.
+      expect(result.length).toBeGreaterThan(0)
+      expect(result.every((s) => s.isPublished === false && s.id === null)).toBe(true)
+    })
+  })
+
   // -------------------------------------------------------------------------
   // createManualSlot
   // -------------------------------------------------------------------------

packages/server/src/time-slot/time-slot.service.ts

@@ -148,13 +148,26 @@ export class TimeSlotService {
 
   /**
    * Return a schedule preview for a given date.
-   * If TimeSlot records already exist → return them (isPublished: true).
-   * Otherwise → derive from the fixed default schedule (isPublished: false).
+   *
+   * Visibility rules (driven by the online mini-program's existing client):
+   * - OPEN/FULL slots are returned with `isPublished: true`.
+   * - CLOSED slots are HIDDEN from preview entirely. The pre-fix admin flow
+   *   used to DELETE these rows on "clear day", but a non-deleting flow
+   *   leaves CLOSED rows behind — the existing mini-program UI does not
+   *   understand the CLOSED status and would render them as "已发布",
+   *   making it look like the clear did not take effect. Hiding them
+   *   preserves the legacy "empty list = rest day" UX until the client
+   *   is republished with CLOSED-aware rendering.
+   * - When the day is entirely CLOSED (a "rest day"), return an empty
+   *   array rather than the default ghost template, so the client shows
+   *   "当日暂无排课" instead of inviting another publish-loop cycle.
+   * - When the day has no rows at all (never generated), return the
+   *   default template as ghost previews (`isPublished: false`).
    */
   async getSchedulePreview(date: string): Promise<ScheduleSlotPreview[]> {
     const parsedDate = new Date(date)
 
-    // 1. Check for existing TimeSlot records (all statuses)
+    // 1. Check for existing TimeSlot records (all statuses).
     const existingSlots = await this.prisma.timeSlot.findMany({
       where: {
         date: { gte: this.toDateOfDay(parsedDate), lte: this.toEndOfDay(parsedDate) },
@@ -162,8 +175,14 @@ export class TimeSlotService {
       orderBy: { startTime: 'asc' },
     })
 
-    if (existingSlots.length > 0) {
-      return existingSlots.map((slot) => ({
+    // 2. Filter out CLOSED — they are admin-closed (typically "rest day")
+    //    and must not surface to the legacy mini-program client.
+    const openSlots = existingSlots.filter(
+      (slot) => slot.status !== TimeSlotStatus.CLOSED,
+    )
+
+    if (openSlots.length > 0) {
+      return openSlots.map((slot) => ({
         id: slot.id,
         date: date,
         startTime: slot.startTime,
@@ -177,6 +196,12 @@ export class TimeSlotService {
       }))
     }
 
+    // 3. All rows for the day are CLOSED → admin declared a rest day.
+    //    Return [] so the client shows the "no slots" empty state.
+    if (existingSlots.length > 0) {
+      return []
+    }
+
     // 2. No existing slots — use fixed default schedule
     const defaultSlots = getDefaultTimeSlots()