Add built-in decoder interface type

ram/ram/__init__.py

@@ -1,4 +1,4 @@
 from ram.utils import git_suffix
 
-__version__ = "0.12.4"
+__version__ = "0.12.5"
 __version__ += git_suffix(__file__)

ram/ram/settings.py

@@ -171,6 +171,7 @@
 DEFAULT_CARD_IMAGE = "coming_soon.svg"
 
 DECODER_INTERFACES = [
+    (0, "Built-in"),
     (1, "NEM651"),
     (2, "NEM652"),
     (3, "PluX"),

ram/roster/migrations/0027_alter_rollingstock_decoder_interface.py

@@ -0,0 +1,29 @@
+# Generated by Django 5.0.4 on 2024-04-30 09:06
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("roster", "0026_rollingstock_item_number_slug"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="rollingstock",
+            name="decoder_interface",
+            field=models.PositiveSmallIntegerField(
+                blank=True,
+                choices=[
+                    (0, "Built-in"),
+                    (1, "NEM651"),
+                    (2, "NEM652"),
+                    (3, "PluX"),
+                    (4, "21MTC"),
+                    (5, "Next18/Next18S"),
+                ],
+                null=True,
+            ),
+        ),
+    ]