solana-driver: Add solana-rpc crate and hold RPC wrapper in API struct

[tilacog]

Description

Follow up to PR #4741, addressing reviewer feedback.

Changes

• Added a new solana-rpc crate, hoping other solana related crates in this repo can use it too.
  • @squadgazzz: following @MartinquaXD's comment, the intention is that the solana-indexer eventually reuses this crate, replacing the rpc module from PR feat(solana-indexer) PR 12: RPC client adapter #4739. Please let me know if you want me to adjust anything in this PR with that in mind.
• The RPC wrapper is now held by the API struct, matching the EVM Driver setup more closely.

How to test

$ cargo test -p solana-driver

[claude]

Claude finished @tilacog's task in 3m 40s —— View job

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PR Review: solana-rpc crate & RPC wrapper in API struct

Nice cleanup — extracting the RPC construction into a reusable crate and moving the client onto the Api struct both read well, and the bind(&self) / serve(self) split mirrors the EVM driver setup nicely. The scaffolding (#[expect(dead_code)]) is clearly intentional for follow-ups.

I left 2 minor, non-blocking inline comments:

• crates/solana-driver/Cargo.toml — solana-commitment-config is now unused in solana-driver and can be removed; solana-client is now test-only and could move to [dev-dependencies].
• crates/solana-rpc/Cargo.toml — the serde feature on url isn't used by the crate.

Nothing blocking. Regarding the solana-indexer reuse question in the description: the SolanaRPC wrapper with an inner() escape hatch + From<RpcClient> looks flexible enough for the indexer to adopt and retire its own rpc module later.

Note: the SolanaRPC naming (vs. SolanaRpc) is consistent with existing repo precedent (e.g. SolverCompetitionAPI) and won't trip clippy's upper_case_acronyms, so I didn't flag it.

• Read the diff and changed files
• Analyze new solana-rpc crate
• Analyze API struct changes
• Post inline comments & summary

[squadgazzz]

solana-rpc is a published crate. IIRC, Cargo only allows one package per name in a dependency graph, so the day any dependency pulls the upstream one, the workspace stops resolving. Probably worth a name that's clearly ours before anything depends on it, cow-solana-rpc or similar, wdyt?

[tilacog]

Oof, I didn't realize that.
cow-solana-rpc it is then!
Renamed in 6af12aa, thanks