Project configuration view: manage a project's statuses

New /projects/:id/configure view, linked from a new 'Configure' item on
the project view's Manage menu.

Backend:
- CardStatusRepository/CardStatusController gain full CRUD: create
  (appended at the end), reorder (dense positions, like card
  ordering), and delete.
- Deleting a status with cards attached is rejected with 409 and
  error.details.card_count, rather than hitting the existing FK
  RESTRICT constraint -- retrying with { reassign_to: <status id> }
  moves those cards to that status first (CardRepository::
  reassignStatus, appended after the destination's existing cards)
  and deletes in one transaction (CardStatusRepository::transaction,
  shared PDO connection across repositories).
- The last status in a project can't be deleted, since a project card
  is required to have one.
- Routes: POST/DELETE .../statuses(/:id), PUT .../statuses/order.
- 14 new CardStatusTest cases covering all of the above.

Frontend:
- ProjectConfigureView.vue: header (title, back-to-project link, the
  shared Manage menu) + a vuedraggable status list (reorder persists
  the whole new order) with a delete button per row and an add-status
  form. A row's plain delete either succeeds immediately or, on 409,
  opens a modal to choose a different status before retrying the
  delete with reassign_to.
- Extracted ProjectManageMenu.vue (the Manage dropdown + delete-project
  modal) out of ProjectView so both views share it; it now also has a
  Configure link (hidden on the configure page itself).
- ApiError gains a cardCount getter (details.card_count), mirroring
  the existing retryAfter getter.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/Repository/CardRepository.php

@@ -214,6 +214,29 @@ final class CardRepository
         return $this->columnCards($ownerId, $projectId, $statusId);
     }
 
+    /**
+     * Move every card in one project status to another status in the same
+     * project -- used when a status is deleted out from under them. Appended
+     * after the destination's existing cards, so both columns stay a dense
+     * 0..n-1 with no repack needed.
+     */
+    public function reassignStatus(int $ownerId, int $projectId, int $fromStatusId, int $toStatusId): void
+    {
+        $ids = $this->idsInColumn($ownerId, $projectId, $fromStatusId);
+        if ($ids === []) {
+            return;
+        }
+
+        $next = $this->nextPositionInColumn($ownerId, $projectId, $toStatusId);
+        $stmt = $this->pdo->prepare(
+            'UPDATE cards SET status_id = :status, position = :position, updated_at = ' . $this->nowExpr() . '
+             WHERE id = :id AND owner_id = :owner'
+        );
+        foreach ($ids as $i => $id) {
+            $stmt->execute(['status' => $toStatusId, 'position' => $next + $i, 'id' => $id, 'owner' => $ownerId]);
+        }
+    }
+
     private function insert(
         int $ownerId,
         ?int $projectId,