Initial commit: VMware vSphere API simulator scaffold.

Add the FastAPI app, PostgreSQL migrations, Docker/Helm packaging, API
contracts, docs, client examples, and the unit/integration/compatibility
test suite for local client and tooling labs without a real vCenter.

app/db/migrate_cli.py

@@ -0,0 +1,16 @@
+"""Apply configured database migrations."""
+
+import asyncio
+
+from app.config import get_settings
+from app.db.migrations import migrate_url
+
+
+async def run() -> None:
+    settings = get_settings()
+    count = await migrate_url(settings.database_url.get_secret_value())
+    print(f"applied {count} migration(s)")
+
+
+if __name__ == "__main__":
+    asyncio.run(run())