Data quality: Negative time_to_release values in escrows

[crtahlin]

Problem

Some escrow records contain negative values for timing metrics:

{
  "id": 39,
  "time_to_release": -14078,
  "time_to_fund": 43,
  "state": "released"
}

Negative `time_to_release` (-14078 seconds ≈ -4 hours) is logically impossible - you can't release before funding.

Observed in

Multiple released escrows have negative timing values. This suggests either:

1. Clock skew between systems
2. Calculation bug in the indexer
3. Events processed out of order
4. Timestamps recorded incorrectly

Impact

• Minor: Metrics/analytics would be incorrect
• Could indicate deeper indexer issues
• Erodes trust in platform data accuracy

Expected Behavior

All timing metrics should be:

• Non-negative (≥ 0)
• Logically consistent (fund → commit → release → claim order)

Suggested Fix

1. Investigate root cause - Check indexer logic for timing calculations
2. Add validation - Reject/flag negative values on write
3. Clean up data - Set invalid values to null or recalculate from timestamps

Acceptance Criteria

• Root cause identified
• New escrows have valid timing metrics
• Existing invalid data cleaned up or flagged

[crtahlin]

Addressed in PR #37