fix(auth): pin native auth storage operations

backend/test/auth-dynamic-registry.test.ts

@@ -6,7 +6,7 @@ import { stringify } from "yaml";
 import { buildApp, type AppWithAuthSessionStore } from "../src/app.js";
 import { loadAuthenticationConfig } from "../src/auth/config.js";
 import { loadConfig } from "../src/config.js";
-import { prepareAuthStateRoot } from "./auth-test-fixtures.js";
+import { createFixtureAuthStorageBridge, prepareAuthStateRoot } from "./auth-test-fixtures.js";
 
 const password = "correct horse battery staple";
 const passwordHash = "$argon2id$v=19$m=65536,t=3,p=1$AAECAwQFBgcICQoLDA0ODw$DRo8ZSPI8G5OCvnFFapbVEjP69aDjy1Sw9i2743cPC4";
@@ -54,7 +54,7 @@ test("each login and session resolve uses the current config snapshot users file
     THT_AUTH_CONFIG_FILE: authFile,
     THT_AUTH_STATE_ROOT: authStateRoot,
     THT_HARNESS_DIR: "/tmp/h",
-  }));
+  }), { authStorageBridgeForTest: createFixtureAuthStorageBridge() });
   cleanups.push(async () => {
     await app.close();
     rmSync(directory, { recursive: true, force: true });