feat: series-aware schedule edits + waitlist ledger removal (M32)

PATCH /v1/catalog/class-schedules/:id patches a recurring rule and,
with applyToFuture, retimes materialized future sessions to the new
local start time on their existing dates — moving confirmed and
waitlisted bookings with them and re-arming reminders. Zones-page
schedule rows gain an inline editor (CS/EN).

Also drops the vestigial waitlist_entries table (migration 00020):
positions derive from bookings.created_at, so the ledger was written
but never read.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/internal/bookings/customer_service_test.go

@@ -164,17 +164,6 @@ func seedMoveBooking(t *testing.T, repo *db.MemoryRepository, sessionID, referen
 	if err != nil {
 		t.Fatalf("get session: %v", err)
 	}
-	if status == "waitlisted" {
-		if err := repo.AppendWaitlistEntry(ctx, db.WaitlistEntryParams{
-			TenantID:       moveTenantID,
-			ClassSessionID: sessionID,
-			CustomerName:   "Move Customer",
-			CustomerEmail:  "[email protected]",
-			Position:       1,
-		}); err != nil {
-			t.Fatalf("seed waitlist entry: %v", err)
-		}
-	}
 	created, err := repo.CreateBooking(ctx, db.CreateBookingParams{
 		TenantID:       moveTenantID,
 		ClassSessionID: &sessionID,