L2: Implement Solana chain module

[Pattermesh]

Level: L2 (1-2 days) | Chain: Rust Systems & L2

What

Arka lists Solana as a "Planned" chain. Implement the Solana backend.

Acceptance Criteria

• New module chain/solana.rs implementing the Chain trait
• Support: connection, balance check, SOL transfer, SPL token transfer
• Uses solana-client crate
• Tests with solana-test-validator
• Update examples/multi_chain.rs
• README updated

Rewards

Contributions are recognized through the kcolbchain contributor tier system. Substantial features are prioritized for discretionary settlement. See CONTRIBUTING.md.

[syutoutousai]

I'd like to work on this — implementing a Solana chain module for arka. I have Solana experience and will submit a PR.

[syutoutousai]

I'd like to work on this! I'll analyze the codebase and submit a PR shortly. #AutoClaimed

[copernicusjones]

Taking this one.

[phachon]

/opire try