OpenCode Zen serves muse-spark-1.2 and muse-spark-1.2-contributor-free only on the OpenAI Responses API endpoint, not /chat/completions. Declares targetFormat: "openai-responses" for both so requests route correctly instead of returning null/empty content. Closes#10867.
Validated in an isolated worktree boarded onto origin/release/v3.8.50 (0 conflicts, 1 file):
- Added a TDD regression test (tests/unit/opencode-muse-spark-responses-10867.test.ts) since the PR had none — confirmed RED against origin/release/v3.8.50 (entries absent) and GREEN on this branch, pushed fix-in-place.
- check-file-size, check-changelog-integrity: OK.
- typecheck:core: clean.
- check-complexity / check-cognitive-complexity: OK, both under baseline.
Co-authored-by: zoser69 <zoser69@users.noreply.github.com>
