fix(gate-66): an availability-guarded lookup is correct, not a violation

[rubenvdlinde]

This is what stopped a fleet-wide script from running over 1,263 call sites — and it would have been a regression in every one of the 106 it touched.

Measured on portaliq:

if ($this->isOpenRegisterAvailable() === false) {   // isInstalled('openregister')
    return ['success' => false, 'message' => 'OpenRegister is not installed or enabled.'];
}
try { $cfg = $this->container->get('OCA\OpenRegister\Service\ConfigurationService'); }

Injecting that dependency makes the service unconstructable on an instance without OpenRegister and turns the clean message into a 500 — the exact failure ADR-083 rule 3 exists to prevent. The app was already right; the gate was wrong to report it.

The rule, refined

Rule 1 governs unconditional dependencies. Where a class reaches for OpenRegister only after establishing it is there, deferring construction is the point and the lookup stays. The finding text now offers both remedies instead of only injection.

File-scoped deliberately: per-method scoping would flag the helper that does the reaching while clearing the caller that does the checking.

Measured effect

Fleet split: 106 guarded, 1,000 unguarded.

	before	after
portaliq / scholiq / doriath / hermiq	1 each	0
pipelinq	192	192
decidesk	120	120
opencatalogi	57	57

Tests

16, both directions pinned: the guarded shape passes, and the same shape with the availability check removed still fails, so the clause cannot go quiet.

clean/ gains OptionalCapabilityService.php, carrying the exact construct planted/ is reported for — if the availability clause is ever lost, that arm goes red. Acceptance matrix: 146 passed, 0 failed.