Walking ~40+ plugin TOMLs via the GitHub Contents API from the worker
exceeded the Workers Free 50-subrequest-per-invocation limit, leaving
the daemon's signed plugins index either empty or partial after every
forced refresh.
Move the walk into the repo: scripts/build-plugins-index.mjs reads each
plugins/<name>/plugin.toml directly from the checked-out tree and emits
a sorted flat array (name, version?, description?, needs?) at
plugins-index.json. The CI workflow regenerates and commits this file
on every push under plugins/, then pokes the worker's
/api/registry/refresh — which now fetches the single committed
plugins-index.json (1 subrequest), validates the JSON shape, and
re-signs it with Ed25519. Refresh cost is now constant in registry
size, not linear.
The dashboard's dict-shaped /api/registry payload is unchanged — that
still rebuilds via the daily 02:00 UTC cron.
