* fix(multi-instance): publish skill_manage cache resets and tolerate a concurrent namespace create
Two leftovers from the multi-instance work (#7097).
The agent's skill_manage tool refreshed only its own process's skills
prompt cache after a create, edit, patch, delete, write_file or
remove_file, so a Gateway replica sharing the home volume kept rendering
that user's previous skill list. Every mutation now runs one drained tail,
as the skill routes do: the write and its history record, the local
refresh, then publish_skills_cache_reset(user_id=...) off the event loop.
A run cancelled while the write is in flight still refreshes and
publishes before the cancellation propagates. A marker that cannot be
written is logged inside the tail and raised as SkillCacheResetPublishError
with a message saying the change was applied, so the model does not retry
a write that succeeded.
Two provisioner replicas starting together against a missing
K8S_NAMESPACE both read 404 and both create; the loser's 409 escaped the
lifespan and crashed it. A 409 on create now counts as the namespace
existing, as the Pod and Service creates already do.
Also drops a stale duplicate of the multi-instance "declaration also
drives" note in CONFIGURATION.md.
* docs(changelog): reference #7099 for the multi-instance leftovers
---------
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
