The durable-run events stream (`GET /v1/runs/{id}/events`) hardcoded its own 30 s idle
keepalive, so it still fell outside the ~20 s idle deadline common to remote
OpenAI-compatible clients even after CHAT_COMPLETIONS_SSE_KEEPALIVE_SECONDS dropped to
10 s. Point it at the shared constant so every API-server SSE writer (chat completions,
Responses, native session stream, run events) keeps the wire alive on the same cadence.
Rewrite the salvaged regression test as two invariants: an idle OpenAI stream writes a
`: keepalive` comment inside the remote-client window (module-local fake clock, no global
`time.monotonic`/`asyncio.wait_for` patching, which would also steer asyncio), and the run
events stream follows the shared constant end-to-end through aiohttp. Both are red on
origin/main.
teknium1
8e00832d9b