The collect endpoints were defined as async def but called synchronous
collector.run() directly, blocking the single uvicorn event loop for
up to 15+ minutes during price collection. This caused all other
requests (including auth/login) to hang, making the app unusable.
Backend: Run each collector in a daemon thread with its own DB session,
returning HTTP 200 immediately. The collector logs status to JobLog as
before, which the frontend can poll.
Frontend: Auto-poll job status every 3s while any job is "running",
with a visual indicator. Disable collect buttons during active jobs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>