quarantine 31 rate-limited results from official runs

Moved 31 task results with score=0 and duration <30s to
runs/official/_quarantine/rate_limited_20260311/. These were
subscription rate-limit hits where the agent returned "hit your limit"
immediately. All from old haiku runs (pre-March 8). Regenerated
MANIFEST.json and official results export.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sjarmak