feat: show comment field for locked environment variables

When an environment variable is locked (is_shown_once=true), the comment field is now displayed as disabled/read-only for future reference. This allows users to see the documentation/note about what the variable is for, even when the value is hidden for security.

The comment field appears after the key field and before the configuration checkboxes in the locked view.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

resources/views/livewire/project/shared/environment-variable/show.blade.php

@@ -21,6 +21,12 @@
                         step2ButtonText="Permanently Delete" />
                 @endcan
             </div>
+            @if ($comment)
+                <div class="w-full">
+                    <x-forms.input disabled id="comment" label="Comment"
+                        helper="Documentation for this environment variable." maxlength="256" />
+                </div>
+            @endif
             @can('update', $this->env)
                 <div class="flex flex-col w-full gap-3">
                     <div class="flex flex-wrap w-full items-center gap-4">