fix: shared template context injection

app/Liquid/Tags/PluginRenderTag.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Liquid\Tags;
+
+use Keepsuit\Liquid\Render\RenderContext;
+use Keepsuit\Liquid\Support\MissingValue;
+use Keepsuit\Liquid\Tags\RenderTag;
+
+/**
+ * Render tag that injects plugin context (trmnl, size, data, config) into partials
+ * so shared templates can use variables like trmnl.user.name without passing them explicitly.
+ */
+class PluginRenderTag extends RenderTag
+{
+    /**
+     * Root-level keys from the plugin render context that should be available in partials.
+     *
+     * @var list<string>
+     */
+    private const PARENT_CONTEXT_KEYS = ['trmnl', 'size', 'data', 'config'];
+
+    protected function buildPartialContext(RenderContext $rootContext, string $templateName, array $variables = []): RenderContext
+    {
+        $partialContext = $rootContext->newIsolatedSubContext($templateName);
+
+        foreach (self::PARENT_CONTEXT_KEYS as $key) {
+            $value = $rootContext->get($key);
+            if ($value !== null && ! $value instanceof MissingValue) {
+                $partialContext->set($key, $value);
+            }
+        }
+
+        foreach ($variables as $key => $value) {
+            $partialContext->set($key, $value);
+        }
+
+        foreach ($this->attributes as $key => $value) {
+            $partialContext->set($key, $rootContext->evaluate($value));
+        }
+
+        return $partialContext;
+    }
+}