fix: bound render-summary strings, restore postdata globals, drain buffers

Review fix round 1 for lit/page-render-summary: extract shared Text::shorten()
(reused by NodeSummary), replace data: URIs with a short marker, prefer
data-src/data-lazy-src over placeholder src, dedup nested p/li/blockquote
text and ignore script/style/noscript content, restore every setup_postdata
global (not just $post), drain output buffers robustly around the_content,
and disclose that rendering can trigger oEmbed/network requests.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/Integrations/WordPress/Render/PageRenderer.php

@@ -9,28 +9,60 @@ use WP_Post;
 /**
  * Renders the content area of an entry in-process, like the front end does for the_content
  * (Divi 5 renders its blocks there – verified in DDEV). Header, footer and Theme Builder
- * layouts are not part of it. Not final so abilities can be unit-tested with a mock.
+ * layouts are not part of it. Rendering runs every plugin's/theme's content filters and
+ * shortcodes exactly as the front end would, which can trigger network requests (e.g. oEmbed
+ * lookups) that get cached by WordPress or other plugins as a side effect. Not final so
+ * abilities can be unit-tested with a mock.
  */
 class PageRenderer
 {
+    /**
+     * Globals setup_postdata() populates from the post loop (WP_Query::the_post()); all of
+     * them are restored to their pre-render value afterwards, not just $post itself.
+     */
+    private const POSTDATA_GLOBALS = ['id', 'authordata', 'pages', 'page', 'more', 'numpages', 'multipage'];
+
     public function render(WP_Post $post): string
     {
-        $previous = $GLOBALS['post'] ?? null;
+        $previousPost = $GLOBALS['post'] ?? null;
+        $previousGlobals = [];
+        foreach (self::POSTDATA_GLOBALS as $name) {
+            $previousGlobals[$name] = $GLOBALS[$name] ?? null;
+        }
+
         $GLOBALS['post'] = $post;
-        setup_postdata($post);
+        $level = ob_get_level();
         ob_start();
         try {
+            setup_postdata($post);
             $html = (string) apply_filters('the_content', (string) $post->post_content);
         } finally {
-            $echoed = (string) ob_get_clean();
-            $GLOBALS['post'] = $previous;
-            if ($previous instanceof WP_Post) {
-                setup_postdata($previous);
-            } else {
-                wp_reset_postdata();
+            $echoed = self::drain($level);
+            $GLOBALS['post'] = $previousPost;
+            foreach ($previousGlobals as $name => $value) {
+                $GLOBALS[$name] = $value;
             }
         }
 
         return $echoed . $html;
     }
+
+    /**
+     * Pops every output buffer opened while rendering, including one a rogue shortcode/filter
+     * left open (drained here instead of leaking into the caller) – but never one it already
+     * closed for us: the loop only pops down to the level recorded before our own ob_start(),
+     * so a filter that closes one buffer too many simply loses whatever was already echoed
+     * (nothing left to drain) rather than us popping a buffer that belongs to the caller.
+     * Buffers are combined in the order their content was written (innermost popped first,
+     * then prepended) so a leaked nested buffer's output stays after what came before it.
+     */
+    private static function drain(int $level): string
+    {
+        $output = '';
+        while (ob_get_level() > $level) {
+            $output = (string) ob_get_clean() . $output;
+        }
+
+        return $output;
+    }
 }