feat(ibc): add Phase 14 Milestone 1 - Cross-Chain IBC Interoperability
Implements full Inter-Blockchain Communication (IBC) protocol:
synor-ibc crate (new):
- Light client management (create, update, verify headers)
- Connection handshake (4-way: Init, Try, Ack, Confirm)
- Channel handshake (4-way: Init, Try, Ack, Confirm)
- Packet handling (send, receive, acknowledge, timeout)
- Merkle commitment proofs for state verification
- ICS-20 fungible token transfer support
- Atomic swap engine with HTLC (hashlock + timelock)
IBC Bridge Contract (contracts/ibc-bridge):
- Token locking/unlocking for cross-chain transfers
- Relayer whitelist management
- Channel registration and sequence tracking
- HTLC atomic swap (create, claim, refund)
- Event emission for indexing
- 52KB optimized WASM binary
Test coverage: 40 tests passing
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