fix: AI assistant in note-input still searches other notes when scoped to "this note"

When chatScope is "this note", the AI had access to note_search and note_read
tools which let it pull content from any note. Now these tools are excluded via
a webOnly flag in buildToolsForChat — only web_search/web_scrape remain if
the user toggled web search.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/app/api/chat/route.ts

@@ -419,7 +419,11 @@ Never switch to another language. Even if the user writes in a different languag
     webSearch: !!webSearch,
     config,
   }
-  const chatTools = toolRegistry.buildToolsForChat(chatToolContext)
+  // When scoped to "this note", only provide web tools — no note_search/note_read
+  // to prevent the AI from pulling information from other notes
+  const chatTools = noteContext
+    ? toolRegistry.buildToolsForChat({ ...chatToolContext, webOnly: true })
+    : toolRegistry.buildToolsForChat(chatToolContext)
 
   // 8. Save user message to DB before streaming
   if (isNewMessage && lastIncoming) {