fix(scripts): check.sh says what it covered, on stdout (#336)

[JArmandoAnaya]

Closes #336.

The issue's first criterion was already met by PR #249 — the script aborts on a missing node_modules rather than limping on. What survived is that it says so on stderr, leaving stdout empty, so a caller capturing stdout sees a partial run and a full one as the same thing: some green pytest output, then silence. The exit code is right, and nobody reads an exit code out of a transcript. It is the same false-calm failure the script's own header warns about for | tail, arriving from the other direction.

What changed

One last line on stdout, from a trap … EXIT — so a require_node_modules three groups deep cannot skip it, which is the exact run that most needed to say something:

check.sh: PASSED  ran=python,frontend,generated,browser  skipped=none
check.sh: PASSED  ran=frontend,generated  skipped=python,browser
check.sh: INCOMPLETE  ran=none  skipped=python,frontend,generated,browser

• ran= is what completed, never what was asked for — recorded after each group's function returns, so a group that aborted partway through is never counted as covered. skipped= is every group the script knows that is not in it.
• Three outcomes, because two would blur the news. FAILED is a step reporting a problem; INCOMPLETE is the run leaving early, where nothing was found wrong with the tree and the checks simply did not happen.
• The browser banner now follows what ran, not what was requested — which is what its own comment always claimed ("a partial run is the same lie however it was asked for"), and was not true of a run that asked for everything and died in frontend. It stays quiet when nothing ran, so unknown group 'nope' is not buried under twelve lines about Playwright.
• Ordering is unchanged in spirit: the banner still comes after the verdict it qualifies — now after the machine-readable line as well, since that is the line it is qualifying.

Written without arrays for the accumulator (ran is a comma string): macOS ships bash 3.2, where an empty array under set -u is an unbound variable. That constraint is already documented in the timing block; this way there is nothing to remember.

Found, not fixed

Nothing.

Test plan

New tests/scripts/check_stages.test.mjs — 8 cases, ~0.2s, no new dependency. Two halves that fail differently:

• Behavioural — copies the real script into a temp root with nothing in it (the issue's own reproduction) and runs it. generated → exit 2 with the verdict line on stdout alone; python → FAILED ran=python; an unknown group → INCOMPLETE ran=none; the banner quiet with nothing run and loud when browser was requested but never reached. The subprocess gets a PATH without uv or pnpm, so every step fails identically on every machine rather than depending on what happens to be installed.
• Static — the group roster, the dispatch case, the default list, --fast, and the trap. This half exists because the way the script rots is not a deleted line but a group quietly leaving the loop: coverage shrinks, every remaining stage passes, and the verdict says PASSED about a smaller run than the reader believes.

Mutation checks, anchors asserted before and after each patch

mutation	caught by
trap summary EXIT commented out	6 of 8
ran never recorded	3
browser dropped from ALL_GROUPS	5
browser) run_browser ;; deleted from the dispatch	1 — the static roster test, and nothing else
the default run drops generated	1

The fourth is the one the issue is really about: every behavioural test stays green while the script silently stops running a quarter of the gate. That is why the static half is there.

Full gate, staged against the harness's ~10-minute ceiling

Test directories derived from ls tests/ at run time.

stage	exit
pytest tests/architecture tests/cli tests/examples tests/formats tests/jobs tests/packaging tests/scripts tests/test_versioning.py	0 (522)
pytest tests/kernel tests/mcp tests/server	0 (2080)
ruff check . / ruff format --check . / mypy src/visionset / lint-imports	0 / 0 / 0 / 0
check.sh frontend generated	0 — and it ended check.sh: PASSED ran=frontend,generated skipped=python,browser
CI=1 npx playwright test	0 (197 passed, 3.0m)
CI=1 npx playwright test -c playwright.cycle.config.ts	0 (1 passed, 36.7s)