diff --git a/src-tauri/src/commands/llm.rs b/src-tauri/src/commands/llm.rs
index 970d43e..5c820e2 100644
--- a/src-tauri/src/commands/llm.rs
+++ b/src-tauri/src/commands/llm.rs
@@ -412,11 +412,19 @@ pub async fn cleanup_transcript_text_cmd(
 /// synchronous llama-cpp inference) is wrapped in spawn_blocking so it
 /// does not stall the Tauri runtime, with the same App-Nap power
 /// assertion the other LLM commands use.
+///
+/// Trust-4 (conf 85, code-atomiser-fix 2026-05-12): added the
+/// `ensure_main_window` guard that every other command in this file
+/// already enforces. The `window: tauri::WebviewWindow` parameter is
+/// injected by Tauri automatically — frontend invoke call sites
+/// (HistoryPage) do not need updating.
 #[tauri::command]
 pub async fn extract_content_tags_cmd(
+    window: tauri::WebviewWindow,
     state: State<'_, AppState>,
     transcript: String,
 ) -> Result<ContentTags, String> {
+    ensure_main_window(&window)?;
     if !state.llm_engine.is_loaded() {
         return Err("LLM not loaded. Download an AI model in Settings.".to_string());
     }