Kept the hard timeout and worker reap for steady-state embed requests while allowing first-use runtime installation and model bootstrap to finish without SIGKILL stranding the install lock.
Added deterministic coverage for initialization outliving the embed timeout budget and corrected the changelog contract.
Fixes#7352
Embed-worker init/embed requests awaited the reply with no timeout, so a
wedged fastembed/onnxruntime runtime blocked the turn memory recall or the
shutdown consolidation forever, hanging headless -p/--mode json runs and
leaving __omp_worker_mnemopi_embed unreaped. The #5753 fix only bounded the
dispose-time consolidate await, not the embed IPC beneath it.
Bound every request with an unref-ed timeout; on expiry fail the request
and SIGKILL-reap the worker so the next call respawns a fresh child.
Fixes#7352
roboomp