fix: track migrations; installs apply them instead of generating them

The *migrations/* ignore rule is removed. appsettings, computes and
logs pin default_auto_field to AutoField, so makemigrations --check
reports no pending BigAutoField migrations and existing installs need
no schema change.

The Vagrant provisioning no longer runs makemigrations, which created
install-specific migration files that conflict with the committed
history; it only runs migrate.

logs/apps.py

@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class LogsConfig(AppConfig):
+    name = "logs"
+    default_auto_field = "django.db.models.AutoField"