CONV-084: Add format step guard

app/Livewire/Dashboard/DashboardConverter.php

@@ -58,6 +58,26 @@ public function storeUpload(StoreUploadedFileAction $storeUploadedFile): void
         $this->step = 'format';
     }
 
+    public function goToFormatStep(): void
+    {
+        if ($this->currentFile === null) {
+            $this->currentFileId = null;
+            $this->step = 'upload';
+
+            return;
+        }
+
+        $this->step = 'format';
+    }
+
+    public function ensureValidStep(): void
+    {
+        if ($this->step === 'format' && $this->currentFile === null) {
+            $this->currentFileId = null;
+            $this->step = 'upload';
+        }
+    }
+
     public function replaceFile(): void
     {
         $this->resetCurrentUpload();

tests/Feature/Livewire/DashboardConverterTest.php

@@ -1,6 +1,8 @@
 <?php
 
 use App\Livewire\Dashboard\DashboardConverter;
+use App\Models\FileRecord;
+use App\Models\User;
 use Livewire\Livewire;
 
 it('renders empty upload state', function () {
@@ -9,3 +11,39 @@
         ->assertSee('PNG, JPG, WEBP and PDF supported in beta')
         ->assertSee('Choose file');
 });
+
+it('does not allow format step without uploaded file', function () {
+    Livewire::test(DashboardConverter::class)
+        ->set('step', 'format')
+        ->call('ensureValidStep')
+        ->assertSet('step', 'upload');
+});
+
+it('returns to upload step when current file is missing', function () {
+    Livewire::test(DashboardConverter::class)
+        ->call('goToFormatStep')
+        ->assertSet('step', 'upload')
+        ->assertSee('Drop your file here');
+});
+
+it('handles a stale current file id by returning to upload step', function () {
+    $user = User::factory()->create();
+
+    Livewire::actingAs($user)
+        ->test(DashboardConverter::class)
+        ->set('currentFileId', 999999)
+        ->call('goToFormatStep')
+        ->assertSet('step', 'upload')
+        ->assertSet('currentFileId', null);
+});
+
+it('opens the format step when a current file exists', function () {
+    $user = User::factory()->create();
+    $file = FileRecord::factory()->for($user)->create(['extension' => 'png']);
+
+    Livewire::actingAs($user)
+        ->test(DashboardConverter::class)
+        ->set('currentFileId', $file->id)
+        ->call('goToFormatStep')
+        ->assertSet('step', 'format');
+});