- MODEL_CAPACITY_EXHAUSTED now uses independent retry strategy:
- retryDelay < 20s: wait actual retryDelay then retry once
- retryDelay >= 20s or missing: retry up to 5 times at 20s intervals
- Still capacity exhausted after retries: switch account (failover)
- Different error during retry (e.g. 429): handle by actual error code
- No model rate limit set (capacity != rate limit)
- Remove Antigravity extra failover retries feature:
Same-account retry mechanism (cherry-picked) makes it redundant.
Removed: antigravityExtraRetries config, sleepFixedDelay, skip-non-antigravity logic.