Add @HuiNeng6 to CONTRIBUTORS.md

[HuiNeng6]

Bounty Claim

Adding my name to CONTRIBUTORS.md as per Issue #441.

Discord: HuiNeng
Interests: AI agents, automation, blockchain development

This is a resubmission after the previous PR was closed due to conflicts.

Closes Scottcjn/rustchain-bounties#441

[HuiNeng6]

Ready for review! All conflicts resolved. Please merge when possible. 🙏

[HuiNeng6]

📢 Test Failure Analysis

I've reviewed the test failures and they appear to be unrelated to this PR.

This PR only adds a single line to CONTRIBUTORS.md:
| @HuiNeng6 | HuiNeng | AI agents, automation, blockchain development |

The failing tests are all in:

• est_replay_defense.py (fingerprint hash, replay detection, rate limiting)
• est_replay_defense_standalone.py (standalone replay defense tests)
• est_rip201_bucket_spoof.py (RIP201 bucket spoof)
• est_wallet_review_holds.py (wallet review tests)

These tests involve complex blockchain/fingerprint logic and SQLite tables that don't exist (ingerprint_submissions, ingerprint_rate_limits). This suggests the test infrastructure setup may be incomplete or flaky.

Request: Could a maintainer review the CONTRIBUTORS.md change separately from the test failures? The change is minimal and safe. Thank you! 🙏