feat: persist repository rename identity

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a049a4-ee9f-78e1-9d66-2cb0f9bea3e3

api/services/repository_identity.py

@@ -0,0 +1,23 @@
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from api.models.managed_repo import ManagedRepo
+from api.models.repository_rename import RepositoryForgeIdentity, RepositorySlug
+
+
+def stage_initial_repository_identity(
+    session: AsyncSession, repo: ManagedRepo
+) -> None:
+    """Attach non-guessed identity state to a newly flushed repository row."""
+    if repo.id is None:
+        raise ValueError("repository must be flushed before identity records are staged")
+    session.add_all(
+        [
+            RepositoryForgeIdentity(repo_id=repo.id),
+            RepositorySlug(
+                repo_id=repo.id,
+                slug=repo.slug,
+                kind="canonical",
+                protected=True,
+            ),
+        ]
+    )