feat: replace php migration with django migration

- keep latest legacy version in initial migration file
- move propel schema to api legacy app
- remove legacy upgrade tool

api/libretime_api/legacy/migrations/0012_2_5_14.py

@@ -0,0 +1,28 @@
+from django.db import migrations
+
+from ._migrations import legacy_migration_factory
+
+# SAAS-923
+# Add a partial constraint to cc_pref so that keystrings must be unique
+
+UP = """
+ALTER TABLE cc_pref ALTER COLUMN subjid SET DEFAULT NULL;
+CREATE UNIQUE INDEX cc_pref_key_idx ON cc_pref (keystr) WHERE subjid IS NULL;
+ANALYZE cc_pref;
+"""
+
+DOWN = None
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("legacy", "0011_2_5_13"),
+    ]
+    operations = [
+        migrations.RunPython(
+            code=legacy_migration_factory(
+                target="2.5.14",
+                sql=UP,
+            )
+        )
+    ]