Why: Checkout did not recurse, so go vet failed without deps/agent-intent, and the runner has no SSH key. Evidence: Workflow uses recursive HTTPS checkout, setup-go 1.27, GOPROXY=https://goproxy.cn,direct, and PROJECT.md vet plus test plus race. Impact: vet-and-test runs on ubuntu-latest. SUBMODULE_TOKEN must be set by the owner before checkout can succeed. Refs: feature/agent-stack-r0-r1 Co-authored-by: Cursor <cursoragent@cursor.com>