test(api_remote): rename second-send test to carry _roundtrip_ substring

[TaprootFreak]

Summary

PR #132 added second_send_succeeds_without_prev_commitment_pubkey_field to the api_remote suite. It's a fully mutating roundtrip test (mints via the publisher, broadcasts commit inscriptions, writes into the SMT/MMR) — structurally identical to send_commit_roundtrip_moves_balance in terms of side effects.

The Deploy PRD workflow excludes mutating roundtrips with --skip _roundtrip_ (substring match, see .github/workflows/deploy-prd.yaml:103-145). The new test's name doesn't contain _roundtrip_, so it slipped through the filter and ran against the live PRD node — failing with 422 Unable to get merkle proofs for provided public key because Mainnet block-times are slow enough that the scanner hadn't yet ingested send-#1's commit inscription into the SMT when send-#2 fired.

DEV e2e passes the same test on the same image (Mutinynet block-times are fast enough that the scanner catches up in-window). The PR #135 protocol fix is verified there. This PR is a pure naming-convention restoration — no behavioural change, no production impact, just putting the test back inside the substring-filter contract that's been in place since the suite was first split into PRD-skip vs DEV-full.

Change

Rename in node/tests/api_remote.rs:1957:

• second_send_succeeds_without_prev_commitment_pubkey_field
• → second_send_roundtrip_succeeds_without_prev_commitment_pubkey_field

Update the live-server-analogue docstring cross-reference in node/src/account_node_tests.rs:774 to match. The unit test itself (test_send_coins_second_send_succeeds_without_prev_commitment_pubkey) stays — it isn't under the substring-filter contract and the unit-test naming style differs from the e2e style.

Verification

grep -E '^(async )?fn [a-z_]+_roundtrip_' node/tests/api_remote.rs after the rename:

• mint_roundtrip_lands_balance_and_proof
• send_commit_roundtrip_moves_balance
• second_send_roundtrip_succeeds_without_prev_commitment_pubkey_field

Three matches. username_claim_resolve_lnurlp_roundtrip ends with _roundtrip (no trailing underscore) and therefore doesn't match either the regex above OR the workflow's --skip _roundtrip_ filter — it's currently masked by ZKCOINS_E2E_ALLOW_FEATURE_TRIMMED_SERVER because LNURL is off on the PRD MVP image. Not in scope for this PR; flagged for follow-up.

Test plan

• cargo fmt --check
• cargo clippy -p node -p shared -- -D warnings
• cargo clippy -p node --all-features -- -D warnings
• cargo check --workspace --all-features --tests
• cargo test -p node --lib account_node::tests::test_send_coins_second_send_succeeds_without_prev_commitment_pubkey -- --test-threads=1 — 1 passed
• CI green (slim lane — pure rename, no ci:full needed)
• After deploy: second_send_roundtrip_succeeds_without_prev_commitment_pubkey_field runs on DEV and passes; PRD skips it (no 422 from Mainnet timing race)

Follow-up (out of scope)

• username_claim_resolve_lnurlp_roundtrip should either be renamed to carry _roundtrip_ as a substring (e.g., username_claim_roundtrip_resolves_lnurlp) or the workflow's filter relaxed to roundtrip without trailing underscore.
• The deploy-prd.yaml:103-108 comment claiming "three roundtrip tests" needs updating once the substring contract is canonical across all four.