Integration tests for each new chain watcher #36
Description
Summary
Integration tests for Ethereum, Solana, and Polygon chain watchers using testnets or mocked RPC responses.
Changes
- Ethereum Sepolia testnet integration test
- Solana Devnet integration test
- Polygon Amoy testnet integration test
- Mocked RPC tests for all three chains
Tests
- All integration tests pass
Acceptance Criteria
Multi-chain support is verified against real or realistic test environments.