fix(hub): restore project create payload and stabilize integration DB seed

Explorer POST /projects was dropping projectId/folderId/workspaceDir after a
narrowed response shape, breaking admin-explorer. Make seedTestOrganization
idempotent under shared-DB isolation, force single-worker vitest, and align the
OAuth no-membership redirect expectation with authRoutes.

hub/vitest.config.ts

@@ -3,11 +3,11 @@ import { defineConfig } from "vitest/config";
 export default defineConfig({
   test: {
     include: ["test/**/*.test.ts"],
-    // Integration tests share one DB; run files sequentially to avoid
-    // concurrent truncate/insert races. Unit tests are fast either way.
-    pool: "forks",
-    fileParallelism: false,
+    // Integration tests share one DB. Single worker + sequential files so
+    // TRUNCATE + seed cannot race across files.
+    pool: "threads",
     maxWorkers: 1,
+    fileParallelism: false,
     env: { NODE_ENV: "test" },
   },
 });