Add region code

Distribution/Data/AppDBContext.cs

@@ -544,6 +544,15 @@ public class AppDBContext(DbContextOptions<AppDBContext> options) : DbContext(op
 
         // --- Regional ---
 
+        modelBuilder.Entity<Region>()
+            .Property(r => r.Code)
+            .HasMaxLength(50);
+
+        modelBuilder.Entity<Region>()
+            .HasIndex(r => r.Code)
+            .IsUnique();
+
+
         modelBuilder.Entity<RegionalTarget>()
             .HasIndex(t => new { t.FK_RegionId, t.Period })
             .IsUnique();

Distribution/Data/Seed/MasterDataSeed.cs

@@ -84,8 +84,8 @@ public static class MasterDataSeed
         );
 
         modelBuilder.Entity<Region>().HasData(
-            new Region { Id = WesternRegionId, Name = "Western Province", CreatedAt = SeedDate, IsActive = true },
-            new Region { Id = CentralRegionId, Name = "Central Province", CreatedAt = SeedDate, IsActive = true }
+            new Region { Id = WesternRegionId, Code = "REG-0001", Name = "Western Province", CreatedAt = SeedDate, IsActive = true },
+            new Region { Id = CentralRegionId, Code = "REG-0002", Name = "Central Province", CreatedAt = SeedDate, IsActive = true }
         );
 
         modelBuilder.Entity<Models.Route>().HasData(