Add ownership read model consistency logging

[bamiebot-maker]

Summary

Closes #579
Add a consistency check that detects when the computed sum of holder balances diverges from the stored total supply and emits a structured error log without throwing.

Changes

• Added ownership consistency check utility
• Emitted structured log fields:
  • creator_id
  • stored_supply
  • computed_holder_sum
  • discrepancy
  • detected_at
• Added unit tests for mismatch and match cases

Testing

• Ran:
  node --import ts-node/register --test src/utils/ownershipConsistency.test.ts