* fix(api): default the event loop to asyncio + cancellation-safe commit
The recurring CI e2e segfault traced to uvloop: the harness's
uvicorn.run() auto-selected it while production's serve() path never
consulted Config.loop (stock asyncio, accidentally safe). Every launch
site now resolves ROBOCO_UVICORN_LOOP (default asyncio; uvloop opt-in),
and DbCommitMiddleware's commit-in-send can no longer be interrupted
mid-wire: on cancellation it gets a bounded grace to finish (committed
data survives the 504), else invalidate-and-reraise.
* feat(runtime): expected-stop breadcrumbs attribute container deaths
Two production exit-143s had no attributable source: every orchestrator
kill path now records a short reason breadcrumb, and the exit monitor
consumes it -- an expected stop logs its reason at info, a genuinely
unexpected one logs none_recorded plus docker-inspect diagnostics
(OOMKilled, timestamps) so the next mystery SIGTERM self-identifies.
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Co-authored-by: Renn F <rennf93@users.noreply.github.com>