fix(core): honor commitment for remote account batches

[xternet]

Summary

SurfnetRemoteClient::get_multiple_accounts accepts a caller-selected commitment, but its primary account batch used RpcClient::get_multiple_accounts, which silently applied the client's default commitment. Companion mint/program-account fetches in the same method already used the requested commitment.

Use get_multiple_accounts_with_commitment for the primary batch as well, then extract the contextual response value. This keeps every remote account fetched by the operation at the same requested commitment.

Regression test

The new test records the outgoing JSON-RPC request through a custom RpcSender. It requests confirmed and asserts that the getMultipleAccounts config actually contains "commitment": "confirmed"; before this patch it observed "finalized".

Validation

• cargo +nightly fmt --all -- --check
• cargo test -p surfpool-core surfnet::remote::tests -- --test-threads=1 — 3 passed
• cargo clippy -p surfpool-core --lib --no-default-features — completed with existing repository warnings only
• git diff --check

I also attempted the complete surfpool-core lib suite locally. It reached 469 passing tests before the shared runner exhausted its open-file limit; the remaining failures reported Too many open files, rather than assertion failures from this change. GitHub CI can run the full suite in its normal environment.

[greptile-apps]

Greptile Summary

The PR updates remote batch account fetching to propagate the caller-selected commitment and adds a regression test that inspects the outgoing JSON-RPC request.

• Replaces the default-commitment batch request with get_multiple_accounts_with_commitment.
• Extracts the account list from the contextual RPC response.
• Verifies that a confirmed request sends "commitment": "confirmed".

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
crates/core/src/surfnet/remote.rs	The primary remote account batch now uses the same requested commitment as related account fetches, with focused request-level regression coverage.

_{Reviews (3): Last reviewed commit: "fix(core): honor commitment for remote a..." | Re-trigger Greptile}

[MicaiahReid]

@xternet I'll need commit signature verification here as well.

[xternet]

@MicaiahReid The updated commit is now SSH-signed and shown as Verified by GitHub. Thanks.

[MicaiahReid]

@xternet can we get a rebase?

[xternet]

@MicaiahReid Rebased onto the latest main and resolved the overlap with #764. The commit is verified, and fmt plus all 7 focused remote tests pass locally. Thanks.