Index beta evidence and foreign key child lookups

src/lib/server/backends/schema.ts

@@ -41,6 +41,7 @@ export function migrateNativeInstances(handle: Database.Database): void {
             creation_id TEXT PRIMARY KEY REFERENCES server_deployments(id),
             cleanup_id TEXT NOT NULL UNIQUE REFERENCES server_deployments(id)
         );
+        CREATE INDEX IF NOT EXISTS idx_ec_host_migrations_instance ON ec_host_migrations(instance_id);
     `);
 }