feat(giving): seed default giving categories

API/ROLAC.API/Data/DbSeeder.cs

@@ -5,6 +5,15 @@ namespace ROLAC.API.Data;
 
 public static class DbSeeder
 {
+    private static readonly (string En, string Zh, int Sort)[] GivingCategorySeed =
+    [
+        ("Tithe",            "什一奉獻", 1),
+        ("General Offering", "一般奉獻", 2),
+        ("Special Offering", "特別奉獻", 3),
+        ("Building Fund",    "建堂基金", 4),
+        ("Mission",          "宣教奉獻", 5),
+    ];
+
     private static readonly (string Name, string Description)[] Roles =
     [
         ("super_admin",     "System administrator — full access"),
@@ -37,6 +46,25 @@ public static class DbSeeder
         }
     }
 
+    public static async Task SeedGivingCategoriesAsync(AppDbContext db)
+    {
+        foreach (var (en, zh, sort) in GivingCategorySeed)
+        {
+            if (!db.GivingCategories.Any(c => c.Name_en == en))
+            {
+                db.GivingCategories.Add(new GivingCategory
+                {
+                    Name_en   = en,
+                    Name_zh   = zh,
+                    SortOrder = sort,
+                    IsActive  = true,
+                    // Audit fields are stamped by AuditSaveChangesInterceptor on save.
+                });
+            }
+        }
+        await db.SaveChangesAsync();
+    }
+
     /// <summary>
     /// Seeds roles and (in Development) the default admin account.
     /// Called once on application startup after migrations have been applied.
@@ -49,6 +77,9 @@ public static class DbSeeder
 
         await SeedRolesAsync(roleManager);
 
+        var db = services.GetRequiredService<AppDbContext>();
+        await SeedGivingCategoriesAsync(db);
+
         if (env.IsDevelopment())
             await SeedAdminUserAsync(userManager);
     }