Add image management functionality: introduce Image entity and related API endpoints, update database schema to support image storage, and enhance UI with a new gallery feature for image selection and upload. Update translations for gallery-related terms.

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

@@ -4,6 +4,7 @@ using Microsoft.EntityFrameworkCore.Metadata;
 using TeleWave.Application.Common.Interfaces;
 using TeleWave.Domain.Auth;
 using TeleWave.Domain.Broadcast;
+using TeleWave.Domain.Images;
 using TeleWave.Domain.Library;
 using TeleWave.Domain.Media;
 using TeleWave.Domain.Settings;
@@ -26,6 +27,7 @@ public class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<ScheduleEntry> ScheduleEntries => Set<ScheduleEntry>();
     public DbSet<BumperAsset> BumperAssets => Set<BumperAsset>();
     public DbSet<AppSetting> AppSettings => Set<AppSetting>();
+    public DbSet<Image> Images => Set<Image>();
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {