monitorLineProvider() registers the webhook HTTP route and returns
immediately. Because startAccount() directly returned that resolved
promise, the channel supervisor interpreted it as "provider exited"
and triggered auto-restart up to 10 times.
Await a promise gated on ctx.abortSignal so startAccount stays alive
for the full provider lifecycle, matching the contract expected by the
channel supervisor.
Closes#26478
Co-authored-by: Cursor <cursoragent@cursor.com>