Fix activity-feed test flake: updateJob honors explicit patch.updatedAt; scoped test cleanup

Two-part root cause (found by the lh-ui stream + master together): (1)
src/store/jobs.ts updateJob unconditionally overwrote updatedAt with now(),
silently clobbering any explicit patch timestamp — JobPatch types it as
patchable but the adapter ignored it, so order-sensitive tests rode on
same-millisecond tie-breaking (failed ~4/5 in isolation). The store now
honors patch.updatedAt ?? now() — semantics-preserving for every existing
caller, which never passed updatedAt explicitly. (2) the activity-feed
test's finally wiped the ENTIRE shared data/jobs dir — with node:test
running test files as concurrent processes, that deletes other processes'
live fixtures; cleanup is now scoped to the test's own created ids.

next-env.d.ts

@@ -1,7 +1,7 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
-import "./.next/dev/types/root-params.d.ts";
+import "./.next/types/routes.d.ts";
+import "./.next/types/root-params.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.