Let each workflow watch the due date or the start date

Deck 1.18 added a start date to cards (Card::$startdate), so a workflow
no longer has to mean "overdue". Each rule now carries a date_field
('due' | 'start'), chosen in the settings form next to board and stacks.

Existing rules keep the due date: the new column's default supplies it
for every stored row, so there is no backfill step, and
Workflow::getDateFieldOrDue() covers entities that were never near the
database as well as hand-edited values. The controller is the one place
that rejects an unknown value instead of normalising it - a client
asking for a rule it would not get should hear about it.

The probe for the field is property_exists(), not method_exists():
Deck's entities declare no getter as real code - getStartdate(),
getDuedate(), even getId() all go through Entity::__call(), which
method_exists() ignores by definition. A method_exists() guard would
have been false on every Deck version and would have turned every
start-date rule into a silent no-op.

assertDeckAvailable() now also refuses Deck older than 1.18.0. That
floor cannot live in appinfo/info.xml - neither the server's nor the app
store's schema has an app-to-app dependency element - but
<nextcloud min-version="34"> already implies it, since 1.18.x is the
only Deck release line published for Nextcloud 34.

isOverdue() becomes hasPassed(): one function for both dates, since the
comparison and the argument against Deck's day-truncating
getDaysUntilDue() are identical for either.

Also carries a pending NcSelect icon-alignment fix that was already in
the working tree.

Bump to 34.1.0.

lib/Controller/WorkflowController.php

@@ -56,14 +56,15 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds = [],
 		array $filterLabelIds = [],
+		string $dateField = Workflow::DATE_FIELD_DUE,
 		bool $notifyEmail = false,
 		bool $enabled = true,
 	): DataResponse {
-		$this->validate($title, $boardId, $sourceStackId, $targetStackId);
+		$this->validate($title, $boardId, $sourceStackId, $targetStackId, $dateField);
 
 		$workflow = new Workflow();
 		$workflow->setUserId($this->currentUserId());
-		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $notifyEmail, $enabled);
+		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $dateField, $notifyEmail, $enabled);
 
 		$workflow = $this->workflowMapper->insert($workflow);
 		return new DataResponse($workflow->jsonSerialize(), Http::STATUS_CREATED);
@@ -82,10 +83,11 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds = [],
 		array $filterLabelIds = [],
+		string $dateField = Workflow::DATE_FIELD_DUE,
 		bool $notifyEmail = false,
 		bool $enabled = true,
 	): DataResponse {
-		$this->validate($title, $boardId, $sourceStackId, $targetStackId);
+		$this->validate($title, $boardId, $sourceStackId, $targetStackId, $dateField);
 
 		try {
 			$workflow = $this->workflowMapper->findForUser($id, $this->currentUserId());
@@ -93,7 +95,7 @@ class WorkflowController extends OCSController {
 			throw new OCSNotFoundException('Workflow not found');
 		}
 
-		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $notifyEmail, $enabled);
+		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $dateField, $notifyEmail, $enabled);
 		$workflow = $this->workflowMapper->update($workflow);
 
 		return new DataResponse($workflow->jsonSerialize());
@@ -147,13 +149,19 @@ class WorkflowController extends OCSController {
 		}
 	}
 
-	private function validate(string $title, int $boardId, int $sourceStackId, int $targetStackId): void {
+	private function validate(string $title, int $boardId, int $sourceStackId, int $targetStackId, string $dateField): void {
 		if (trim($title) === '') {
 			throw new OCSBadRequestException('Title must not be empty');
 		}
 		if ($sourceStackId === $targetStackId) {
 			throw new OCSBadRequestException('Source and target stack must differ');
 		}
+		// Rejected rather than silently normalised to 'due': a client sending
+		// something else is asking for a rule it would not get, and the runner
+		// falls back to the due date without a word.
+		if (!in_array($dateField, Workflow::DATE_FIELDS, true)) {
+			throw new OCSBadRequestException('Unknown date field: ' . $dateField);
+		}
 
 		// Reject references to boards or stacks that are gone (or were never
 		// the user's) instead of storing a workflow that can only fail later.
@@ -190,6 +198,7 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds,
 		array $filterLabelIds,
+		string $dateField,
 		bool $notifyEmail,
 		bool $enabled,
 	): void {
@@ -199,6 +208,7 @@ class WorkflowController extends OCSController {
 		$workflow->setTargetStackId($targetStackId);
 		$workflow->setFilterUserIds($filterUserIds === [] ? null : json_encode(array_values($filterUserIds)));
 		$workflow->setFilterLabelIds($filterLabelIds === [] ? null : json_encode(array_values($filterLabelIds)));
+		$workflow->setDateField($dateField);
 		$workflow->setNotifyEmail($notifyEmail);
 		$workflow->setEnabled($enabled);
 	}