fix(690,758): count the same query a paged handler pages (#833)

Co-authored-by: Timothy <timothy@noreply.gitea.tblindustries.be>

ErsatzTV.Application/ProgramSchedules/Queries/GetPagedProgramSchedulesHandler.cs

@@ -1,4 +1,4 @@
-using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain;
 using ErsatzTV.Infrastructure.Data;
 using Microsoft.EntityFrameworkCore;
 using static ErsatzTV.Application.ProgramSchedules.Mapper;
@@ -13,8 +13,6 @@ public class GetPagedProgramSchedulesHandler(IDbContextFactory<TvContext> dbCont
         CancellationToken cancellationToken)
     {
         await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
-        int count = await dbContext.ProgramSchedules.CountAsync(cancellationToken);
-
         IQueryable<ProgramSchedule> query = dbContext.ProgramSchedules.AsNoTracking();
 
         if (!string.IsNullOrWhiteSpace(request.Query))
@@ -22,6 +20,9 @@ public class GetPagedProgramSchedulesHandler(IDbContextFactory<TvContext> dbCont
             query = query.Where(ps => EF.Functions.Like(ps.Name, $"%{request.Query}%"));
         }
 
+        // count the SAME query the page is taken from, so the two cannot drift (issues #690, #758)
+        int count = await query.CountAsync(cancellationToken);
+
         List<ProgramScheduleViewModel> page = await query
             .OrderBy(ps => ps.Name)
             .Skip(request.PageNum * request.PageSize)