fix(api): correct misleading error message on empty keyValuePairs

[josefbehr]

The problem

ApiController::updateQuestion() rejects an empty keyValuePairs array with:

This form is archived and can not be modified

The form is not archived. The message has nothing to do with the actual cause, which sends callers looking in the wrong place.

Reproduction

Against Nextcloud 32.0.9 / Forms 5.3.3, on a form that is not archived:

PATCH /ocs/v2.php/apps/forms/api/v3/forms/{formId}/questions/{questionId}
Content-Type: application/json

{"keyValuePairs":{}}

400 | This form is archived and can not be modified

Why this looks like a copy-paste leftover

• The logger->info() call on the line directly above already says Empty keyValuePairs, will not update.
• The method's own @throws annotation documents this case as Empty keyValuePairs, will not update
• The sibling methods updateForm() and updateOption() both report it accurately
• The string matches the archived-form check ~20 lines further up verbatim

Scope

Only the message string changes.

There is a related inconsistency I deliberately left alone: the docblock and both sibling methods use OCSForbiddenException (403) for this case, while updateQuestion() uses OCSBadRequestException (400). Aligning them would change the status code for existing clients, and 400 is arguably the more accurate one for an empty payload anyway. Happy to follow up in either direction if you have a preference.

Context

Found while creating a form through the API.

🤖 Generated with Claude Code

[Chartman123]

/backport to stable5.3

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
lib/Controller/ApiController.php	0.00%	1 Missing ⚠️

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