Add wallet balance to User model and implement Atoll/Island management

- Added `wallet_balance` field to the User model.
- Updated UserAdmin to include `wallet_balance` in the admin interface.
- Created serializers and views for Atoll and Island management.
- Implemented endpoints for listing, creating, and updating Atolls and Islands.
- Enhanced payment processing with UUIDs for Payment and Topup models.
- Added migration files for new fields and constraints.
- Improved error handling and validation in various views.
- Updated email templates for better responsiveness and SEO.

billing/migrations/0003_alter_billformula_id_alter_payment_id.py

@@ -0,0 +1,27 @@
+# Generated by Django 5.1.2 on 2025-01-20 14:58
+
+import uuid
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("billing", "0002_billformula_payment_topup_delete_device"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="billformula",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="payment",
+            name="id",
+            field=models.UUIDField(
+                default=uuid.uuid4, editable=False, primary_key=True, serialize=False
+            ),
+        ),
+    ]

billing/migrations/0004_alter_topup_id.py

@@ -0,0 +1,20 @@
+# Generated by Django 5.1.2 on 2025-01-20 15:00
+
+import uuid
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("billing", "0003_alter_billformula_id_alter_payment_id"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="topup",
+            name="id",
+            field=models.UUIDField(
+                default=uuid.uuid4, editable=False, primary_key=True, serialize=False
+            ),
+        ),
+    ]