#2996 made context_compactor call resolve_endpoint('utility', owner=owner),
but the mock added by #2174 stubbed it as lambda which: ..., which rejects the
owner kwarg. Each PR passed alone; merged on dev the two compaction tests fail
with TypeError and the pytest job goes red. Widen the mock to lambda *a, **k.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
On summary LLM call failure, maybe_compact was returning system_msgs+recent
(dropping the older half) with was_compacted=False, misleading the caller into
thinking the list was unchanged. Return the original messages list unchanged so
no history is lost; the next trim_for_context call handles length if needed.
Fixes#2160
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>