feat(env-vars): split production and preview into labelled sections

Preview and production variables were interleaved in one table with a shared
Type column. Drop the Type column and head each scope's rows with a
'Production' / 'Preview deployments' section label, so the two groups read as
separate sections. Rows already carry their scope and are ordered
production-first, so this is presentation-only.

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

@@ -1,5 +1,8 @@
 @php
-    $showEnvironmentType = $showPreview;
+    // Preview and production variables are split into labelled groups instead of a
+    // shared "Type" column, so the column is dropped and rows are headed by scope.
+    $groupByScope = $showPreview;
+    $showEnvironmentType = false;
     $activeFilterCount = count($variableFilters) + count($serviceFilters) + ($environmentFilter !== 'all' ? 1 : 0);
     $filterLabels = [
         'managed' => 'Managed', 'user' => 'User-defined', 'buildtime' => 'Buildtime',
@@ -212,7 +215,14 @@
                             <span class="text-center">Runtime</span>
                             <span></span>
                         </div>
+                            @php $renderedScope = null; @endphp
                             @foreach ($this->environmentVariablePageRows as $row)
+                            @if ($groupByScope && $row['scope'] !== $renderedScope)
+                                @php $renderedScope = $row['scope']; @endphp
+                                <div class="flex items-center gap-2 border-b border-neutral-200 bg-neutral-50 px-4 py-2 text-[12px] font-semibold text-neutral-700 dark:border-white/[0.08] dark:bg-white/[0.03] dark:text-fg">
+                                    {{ $renderedScope === 'preview' ? 'Preview deployments' : 'Production' }}
+                                </div>
+                            @endif
                             @if ($row['kind'] === 'managed')
                                 <livewire:project.shared.environment-variable.show wire:key="{{ $row['id'] }}"
                                     :env="$row['environmentVariable']" :type="$resource->type()" :showEnvironmentType="$showEnvironmentType" />