feat: Add Avalanche C-Chain network support

[AugustoL]

Summary

Add support for Avalanche C-Chain (chain ID: 43114) network exploration in OpenScan.

Context

Avalanche C-Chain is EVM-compatible, making integration straightforward using existing L1 adapters. It's one of the largest L1s by TVL with a strong DeFi ecosystem.

Scope

explorer-network-connectors

• Add Avalanche public RPC endpoints
• Verify compatibility with existing EVM fetchers

explorer-metadata

• Add Avalanche network configuration
• Add Avalanche logo and branding assets
• Add popular Avalanche contract tags (AVAX, Trader Joe, Aave, etc.)

explorer (this repo)

• Add Avalanche to networks.json
• Configure default RPC endpoints
• Test block, transaction, and address pages
• Verify contract verification via Sourcify

Network Details

• Chain ID: 43114
• Currency: AVAX
• Block Explorer: snowtrace.io
• RPC Endpoints:
  • https://api.avax.network/ext/bc/C/rpc
  • https://avalanche.public-rpc.com
  • https://rpc.ankr.com/avalanche

Technical Considerations

• Standard EVM-compatible chain (should work with L1 adapters)
• High throughput - may need pagination tuning
• Snowtrace API for additional data if needed

Labels

enhancement, network-support, good-first-issue