fix(ui): polish create flows and terminal navigation

Open the global terminal outside Livewire navigation, clarify that
image tag and SHA256 digest are mutually exclusive, inset the GitLab
empty state, and show loading on Dockerfile create. Add regression tests.

resources/views/livewire/project/new/simple-dockerfile.blade.php

@@ -6,7 +6,7 @@
                     <h2>Dockerfile</h2>
                     <p>Create an application directly from a Dockerfile without connecting a Git repository.</p>
                 </div>
-                <x-forms.button type="submit" isHighlighted>Create application</x-forms.button>
+                <x-forms.button type="submit" wire:target="submit" isHighlighted>Create application</x-forms.button>
             </div>
             <div class="application-settings-section-body p-0!">
                 <x-forms.textarea useMonacoEditor monacoEditorLanguage="dockerfile" rows="20"