Add settings endpoints and registration status check: implement new API endpoints for settings management, including registration status retrieval, and update the registration command handler to enforce registration rules based on site settings.

backend/src/TeleWave.Infrastructure/Persistence/AppDbContext.cs

@@ -6,6 +6,7 @@ using TeleWave.Domain.Auth;
 using TeleWave.Domain.Broadcast;
 using TeleWave.Domain.Library;
 using TeleWave.Domain.Media;
+using TeleWave.Domain.Settings;
 using TeleWave.Infrastructure.Identity;
 
 namespace TeleWave.Infrastructure.Persistence;
@@ -24,6 +25,7 @@ public class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<Channel> Channels => Set<Channel>();
     public DbSet<ScheduleEntry> ScheduleEntries => Set<ScheduleEntry>();
     public DbSet<BumperAsset> BumperAssets => Set<BumperAsset>();
+    public DbSet<AppSetting> AppSettings => Set<AppSetting>();
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {