Context compression is atomic, but a gateway interrupt (an incoming user
message while the agent is busy) could abort the in-flight summary call.
The Codex Responses aux stream polls the thread interrupt flag and raised
InterruptedError unconditionally — so compression fell back to a degraded
static 'summary unavailable' marker, losing the real handoff (#23975).
Add a thread-local interrupt-protection flag (aux_interrupt_protection
context manager) in auxiliary_client; the Codex stream's cancellation
check honors it. The compressor wraps its summary call_llm in the context
manager. Timeouts still fire (a hung call must die) and all other aux
tasks (vision, web_extract, title_generation, …) stay interruptible.
Re-entrant, so the main-model retry recursion is safe.
Co-authored-by: konsisumer <der@konsi.org>
