4b351c751a made `main` resolve straight to the git branch without reading
releases/channels/main.json (a WAF 403 on that never-published record stopped
updates, #128295). The Desktop source hand-off test still served that record
and asserted apply() fetched it twice, so JS & TS checks went red on every
main push and PR since.
The fixture no longer serves main.json and the test asserts re-resolving main
makes zero requests -- a regression back to reading the record now 404s and
fails the same assertion.
0aa764fedd