fix(server): a handoff too large for the context window no longer wedges the thread#19414

test(server): reproduce Codex handoff failure after a run interrupted before provider start

Merge remote-tracking branch 'origin/main' into fix/issue-23275

docs: explain deferred oversized handoffs

test(server): avoid stale handoff delivery narrowing

test(server): consolidate oversized handoff deferral coverage

fix(server): preserve deferred handoffs through delivery retries

fix(server): a handoff too large for the context window no longer wedges the thread