Add Support for 'Zero-Knowledge' KYC Verification

[gabito1451]

Context

Privacy-preserving identity.

Problem

Users share too much PII with the platform.

Suggested Execution

• Integrate with ZK-KYC providers (e.g., Violet, Galxe).
• Store only the 'Proof' on-chain; NovaFund never sees the raw SSN/Passport.

Acceptance Criteria

• Maximum user privacy.
• Reduced regulatory liability for NovaFund.

References

• backend/src/verification/zk-kyc.service.ts