fix: Complete memory leak fix for shortcode context handling

- Changed shortcode context from boolean to depth counter for nested shortcodes
- Added shortcode context protection to template-wrapper.php for single page views
- Fixes remaining recursion path in single FediStream post views

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

includes/Frontend/TemplateLoader.php

@@ -36,12 +36,13 @@ class TemplateLoader {
     private const MAX_RECURSION_DEPTH = 3;
 
     /**
-     * Whether we're currently in a shortcode rendering context.
-     * When true, the_content filter is skipped to prevent recursive shortcode processing.
+     * Shortcode rendering context depth counter.
+     * When > 0, the_content filter is skipped to prevent recursive shortcode processing.
+     * Using a counter instead of boolean to handle nested shortcodes properly.
      *
-     * @var bool
+     * @var int
      */
-    private static bool $in_shortcode_context = false;
+    private static int $shortcode_context_depth = 0;
 
     /**
      * Enter shortcode rendering context.
@@ -50,7 +51,7 @@ class TemplateLoader {
      * @return void
      */
     public static function enter_shortcode_context(): void {
-        self::$in_shortcode_context = true;
+        ++self::$shortcode_context_depth;
     }
 
     /**
@@ -60,7 +61,9 @@ class TemplateLoader {
      * @return void
      */
     public static function exit_shortcode_context(): void {
-        self::$in_shortcode_context = false;
+        if ( self::$shortcode_context_depth > 0 ) {
+            --self::$shortcode_context_depth;
+        }
     }
 
     /**
@@ -69,7 +72,7 @@ class TemplateLoader {
      * @return bool
      */
     public static function is_in_shortcode_context(): bool {
-        return self::$in_shortcode_context;
+        return self::$shortcode_context_depth > 0;
     }
 
     /**
@@ -253,7 +256,7 @@ class TemplateLoader {
         // Skip the_content filter if:
         // 1. We're in a shortcode context (prevents recursive shortcode processing)
         // 2. We're at depth > 1 (nested data loading)
-        $skip_content_filter = self::$in_shortcode_context || self::$recursion_depth > 1;
+        $skip_content_filter = self::$shortcode_context_depth > 0 || self::$recursion_depth > 1;
 
         $data = array(
             'id'        => $post->ID,