Add broadcast scheduling features: implement Show and Channel entities, enhance AppDbContext and DependencyInjection for broadcasting, and update API routing. Include migration for new database schema and update documentation for broadcast-related functionalities.

backend/src/TeleWave.Application/Common/Interfaces/IAppDbContext.cs

@@ -1,5 +1,7 @@
 using Microsoft.EntityFrameworkCore;
 using TeleWave.Domain.Auth;
+using TeleWave.Domain.Broadcast;
+using TeleWave.Domain.Library;
 using TeleWave.Domain.Media;
 
 namespace TeleWave.Application.Common.Interfaces;
@@ -8,6 +10,9 @@ public interface IAppDbContext
 {
     DbSet<RefreshToken> RefreshTokens { get; }
     DbSet<MediaAsset> MediaAssets { get; }
+    DbSet<Show> Shows { get; }
+    DbSet<Channel> Channels { get; }
+    DbSet<ScheduleEntry> ScheduleEntries { get; }
 
     Task<int> SaveChangesAsync(CancellationToken cancellationToken);
 }