fix(gate-39): a BOUND name is still a name, and [^>]* could not see 19 buttons

[rubenvdlinde]

Part of the a11y gate repair (#222 family).

The false positives

r'(^|\s)(:?aria-label|aria-labelledby|v-bind:aria-label|title)\s*='

:? binds to the first alternative only. :aria-label was accepted; :title, v-bind:title and :aria-labelledby were not. Vue binds nearly every user-visible string, because it has to pass through t():

<button type="button" class="settings-page-editor__remove"
        :title="t('openbuild', 'Remove tab')"
        @click="removeTab(index)">

That button has a name. All 22 of openbuild's findings were this exact shape, and the only way to close them was to add a second, redundant name.

The gate already accepted static title=, so accepting the bound form is a consistency fix, not a new claim about how strong a name title is.

The false negatives, which nobody had counted

<button\b([^>]*)> ends the attribute run at the first > — including one inside an attribute value:

<NcButton :disabled="!staffId || submitting || pin.length >= 6" @click="…">

The old parser ended that tag at pin.length >, took = 6" @click=… as the button's body, found more than two characters in it, and passed.

19 buttons across 6 apps were invisible to this gate for that reason alone:

app	invisible buttons
openregister	8
docudesk	3
pipelinq	3
opencatalogi	2
doriath	2
procest	1

The parser is quote-aware now — which is why pipelinq's count rises 4 → 6 while every other app falls. I checked each of those two by hand; both are real buttons the old regex could not parse.

Measured across 11 repos: 77 → 44

app	before	after
openbuild	22	0
procest	32	24
openregister	7	6
docudesk	5	2
opencatalogi	4	3
pipelinq	4	6 ⬆

Also accepted, on the same "the name arrives" principle

• the camelCase ariaLabel prop form
• an explicit <template #default>, which nc-vue renders as the button's label

The icon slot alone is not a name and is still flagged — that pair is asserted, and mutating the slot rule to accept any <template> turns it red.

Mutation-checked

reverted fix	result
old bind-blind regex restored	6 failures
default-slot acceptance widened to any slot	icon-slot true positive fails

Wiring

A missing or crashing helper now reports SKIPPED (wiring), not PASS (#147 / #249): exit code is a status, findings are stdout, stderr is kept in <log>.err, and the call is wrapped in set +e because gate-19's block leaves errexit on for every gate after it — without that, a failing helper kills the whole runner mid-sweep.

Implementation: scripts/lib/check_button_name.py, 20 tests. Suites: 29 helper suites pass.