feat(adapters): implement 6 remaining EVM protocol adapters

[Patrick-Ehimen]

Summary

• Stargate V2 — OFTSent event; GUID (LZ V2 packet GUID) as correlation key; dest chain from LayerZero endpoint ID
• CCTP V2 — DepositForBurn event; correlation key scoped to source chain (cctp:<chain>:<nonce>); mintRecipient right-unpacked from bytes32
• Hop — TransferSent event; transferId as correlation key; sender not available in log (documented limitation)
• Connext — XCalled event with nested dynamic TransferInfo struct; transferId as correlation key; sender/receiver from params.originSender / params.to
• Wormhole — LogMessagePublished; VAA key (wormhole:<wh_chain>:<sender>:<sequence>) as correlation ID; dest chain is opaque payload (set to None)
• Axelar — ContractCall event; payloadHash as correlation key; dest chain from Axelar chain name string

All adapters follow the ProtocolAdapter trait pattern established in PR #4, with enum dispatch in adapters/mod.rs.

Test Plan

• 28 unit tests across all 6 adapters (cargo test -p indexer) — all passing
• cargo clippy --workspace --all-targets -- -D warnings — clean
• Pre-commit hook (cargo fmt --check + cargo clippy) — passed at commit time
• Each test file covers: happy path, wrong topic → None, unknown dest chain → dest_chain: None, protocol-specific invariant (correlation ID format, amount encoding, etc.)