ISpooferMotion v2.5.6

Restore V1 spoofer download speed (v2.5.6)

Fixes a regression where jobs with a few private assets stalled for 5+
minutes behind the shared rate limiter. Root cause was four V2-only
divergences from V1's download algorithm, all reverted here:

- Only run discovery when no place_id was supplied (was unconditional)
- Removed retry-on-403 loop (403 is terminal for a URL/cookie combo)
- Restored fully parallel graph queries (was throttled to 3 concurrent)
- Retry budget back to 3 attempts / 30s timeout (was 10 / 45s)

Also adds a progress heartbeat every 10 candidate URLs and a bail-out
after 5 consecutive permanent failures so a stuck asset can't hold the
shared rate limiter for a whole job.