privacy: implement confidential transfers (Pedersen commitments + range proofs) (epic) #198
Description
Goal
Implement confidential transaction support per spec: commitments, range proofs, and verification in the tx pipeline.
Current
catalyst-crypto proofs are placeholder; confidential tx validation hooks are not implemented.
Scope
- Commitment schemes and encoding
- Range proof generation/verification
- Mempool + consensus validation rules
- RPC and CLI support for confidential transfers
Acceptance criteria
- Confidential transfers are validated and applied deterministically
- Invalid proofs are rejected with tests
- Performance baselines established