CI: web-e2e proxy-delay spec fails on main since #841, the package page no longer discovers a proxy's package by looking #858

Problem

Since #841 (#836: a proxy's or group's package page answers from the cache) merged, the web-e2e job fails on main (CI run of 28f7b14 and every merge since, e.g. 4f2636a), on the first try and on the retry:

[chromium] › e2e/specs/proxy-delay.spec.ts:33:1 › a delayed proxy version shows the delay badge and is absent from browse

Error: GET package detail dlyproxy1793731283761/Sample.Lib -> 404

   at fetchPackageDetail (web/e2e/helpers.ts:120:22)
   at web/e2e/specs/proxy-delay.spec.ts:59:18

The spec discovers the upstream's Sample.Lib by calling GET /browse/packages/{repo}/{id}, relying on that read to ask the upstream and stamp the version's first_seen_at. Since #841 that request reads the proxy cached only, as intended: a package the proxy holds nothing of is a 404 and is not discovered by looking. Discovery now goes through POST /browse/packages/{repo}/{id}/refresh, which the page offers as Refresh from upstream on its "Package not cached" state.

Like #781, this keeps release.yml from building v2.2.0: it needs a CI run of the tagged commit that passed every job in REQUIRED_JOBS, web-e2e included.

Expected

The spec follows the page's flow: it opens the package page, sees Package not cached, clicks Refresh from upstream, and then finds the version row with the delayed badge, and the detail API (from the cache now) surfaces the version as delayed_until. fetchPackageDetail's comment in web/e2e/helpers.ts no longer says the read discovers a proxy's package. web-e2e passes on main again.