Add application API and OpenAPI docs

app/Http/Requests/Api/MoveProjectTicketRequest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace App\Http\Requests\Api;
+
+use App\Models\Project;
+use App\Models\Ticket;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Support\Arr;
+use Illuminate\Validation\Rule;
+use Illuminate\Validation\Validator;
+
+class MoveProjectTicketRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return $this->user() !== null;
+    }
+
+    /**
+     * @return array<string, ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        /** @var Project $project */
+        $project = $this->route('project');
+
+        return [
+            'ticket_status_id' => [
+                'required',
+                'integer',
+                Rule::exists('ticket_statuses', 'id')->where('project_id', $project->id),
+            ],
+        ];
+    }
+
+    /**
+     * @return array<int, callable(Validator): void>
+     */
+    public function after(): array
+    {
+        return [
+            function (Validator $validator): void {
+                if ($validator->errors()->isNotEmpty()) {
+                    return;
+                }
+
+                /** @var Ticket $ticket */
+                $ticket = $this->route('ticket');
+                $validated = $validator->validated();
+                $ticketStatusId = (int) Arr::get($validated, 'ticket_status_id');
+
+                if ($ticket->ticket_status_id === $ticketStatusId) {
+                    return;
+                }
+
+                $ticket->loadMissing('ticketStatus');
+
+                $isAllowed = $ticket->ticketStatus?->allowedTargetStatuses()
+                    ->whereKey($ticketStatusId)
+                    ->exists() ?? false;
+
+                if (! $isAllowed) {
+                    $validator->errors()->add(
+                        'ticket_status_id',
+                        'Choose a status this ticket is allowed to move to.',
+                    );
+                }
+            },
+        ];
+    }
+}