PHASE-1-SHADOW-RUN: bind VersionSet resolution to model identity

db/migrations/0033_model_registry_identity_contract.sql

@@ -0,0 +1,8 @@
+-- PHASE-1-SHADOW-RUN / REQ-EXEC-001
+-- Bind a client-selected model identity to the server-side approved VersionSet.
+ALTER TABLE governance.model_version_registry
+    ADD COLUMN IF NOT EXISTS model_id uuid;
+
+CREATE INDEX IF NOT EXISTS ix_model_version_registry_model_scope_effective
+    ON governance.model_version_registry (model_id, scope_key, effective_at desc)
+    WHERE model_id IS NOT NULL;