ci: run buzz-workflow and buzz-acp lib tests in the unit gate

[mfanafuthimhlanga]

Summary

just test-unit covers buzz-core, buzz-auth, buzz-voice, buzz-cli, buzz-db --lib, buzz-conformance, buzz-push-gateway, and buzz-backend-kubernetes. buzz-workflow and buzz-acp are referenced by no cargo test or nextest invocation anywhere in .github/workflows/ or scripts/run-tests.sh. buzz-acp appears only in build and release contexts — the Justfile binary loops and sprig.yml.

This is exactly the condition the buzz-backend-kubernetes block immediately above already names:

Enumerated explicitly because nothing in CI runs cargo test --workspace — workspace membership alone buys clippy/check, not a single executed test.

Both crates were enumerated nowhere, so cargo clippy --workspace --all-targets compiled their test targets while nothing executed them.

Crate	Lib tests	Ran in CI before this PR
buzz-workflow	154	no
buzz-acp	661	no

This is the same class of gap as #3461 (buzz-relay: 771 of 804 never execute). This PR does not address buzz-relay — see below.

Why it matters

buzz-acp owns the agent concurrency model: per-channel queues with per-channel in-flight tracking (queue.rs), the fungible worker pool (pool.rs), and mention-filtered per-agent subscriptions (relay.rs). buzz-workflow owns the workflow schema and executor, including the request_approval definition-time validation that WF-08 work (#2377, #3327) touches.

Both are areas with active open bugs, which is consistent with neither having had a test gate.

Verification

Both suites are infra-free and pass clean. Run on a fork, since fork PRs need maintainer approval before workflows execute:

Starting 154 tests across 1 binary (2 tests skipped)
Summary [0.306s] 154 tests run: 154 passed, 2 skipped

Starting 661 tests across 1 binary
Summary [13.080s] 661 tests run: 661 passed, 0 skipped

buzz-acp runs with 0 skipped — no #[ignore]d subset, no infra-gated early returns.

I could not run just ci locally (no working Rust toolchain on this machine), so local fmt/clippy were not run. The change is seven lines of Justfile and CI's own Rust Lint job covers it.

Why buzz-relay is excluded

Deliberately out of scope, and it is why #3461 is not trivially fixable. -p buzz-relay --lib surfaces four tests that need Postgres but are not #[ignore]d:

api::admin::tests::feedback_attachment_rejects_unknown_feedback
api::admin::tests::report_detail_rejects_unknown_report
api::media::tests::media_get_auth_flag_off_allows_unauthenticated_read_until_sidecar_gate
api::media::tests::media_get_auth_flag_on_accepts_range_header_only_after_auth

Each hangs ~30s on a DB connection and then fails, and nextest's fail-fast then cancelled 628 of 840 remaining tests. Marking those four #[ignore] looks like the right first step for #3461, but it is a separate change against a different crate and I did not want to bundle it here.

Note on method

I confirmed these tests were not merely passing-by-default before trusting the result: I added a test, watched CI go green, then inverted the assertion so it had to fail — CI stayed green, which is what surfaced the gap. Under nextest's default profile a test that never runs is indistinguishable from one that passes, so the green run alone proved nothing.

Context: I found this while evaluating the workflow and approval-gate layer, which is where my interest in the codebase is.