## Why
Config reads arriving while a long-running shared read was active waited for that
request to finish, even though they could safely run concurrently.
## What changed
- Admit newly queued shared reads into the active batch until an exclusive write
is queued, preserving the write as a fairness barrier.
- Treat `hooks/list` and `configRequirements/read` as shared config reads.
- Cover concurrent reads, read/write ordering, and config reads completing
alongside a `skills/list` request.
GitOrigin-RevId: 8194301c2ba60be0fc71b8915923af9accc745dc
Charlie Marsh
1d928cad2f