Sibling of #64686: _run_agent's empty-final_response early return dropped
failure_reason (and #64686 only fixed the non-empty path), so downstream
consumers (TUI billing surface, transient-failure persistence) lost the
structured reason exactly when a failed run produced no text.
Also hardens the two BasePlatformAdapter identity checks (edit_message /
delete_message) with getattr so duck-typed adapters without the attribute
mean 'capability absent', not AttributeError — this was crashing the
send_progress_messages path for minimal adapters and test fakes.
The fake _SessionStore tracked peer_records but no test read it, leaving
#55300's peer-record behavior unasserted. Add a positive assertion on the
persist path and negative (== []) assertions on the two stale/moved-binding
skip paths, so the peer-record side effect is bound.
Mutation-verified: removing the production _record_gateway_session_peer call
makes the positive assertion fail.
Co-authored-by: João Vitor Cunha <jvsantos.cunha@gmail.com>
The #55300 peer-recording call now fires on the failed-turn compression
split path; the fake _SessionStore in test_compression_failure_session_sync
(carried in with #55721's test changes) lacked that method. Add a
call-tracking no-op so the combined salvage's tests pass.
Co-authored-by: João Vitor Cunha <jvsantos.cunha@gmail.com>
Salvages PR #25747 by preserving gateway session rotation even when a post-compression model call fails before returning final content.
Co-authored-by: Hermes <127238744+teknium1@users.noreply.github.com>
