Document Invent panel maximize mode feature

build/invent/invent.mdx

@@ -36,7 +36,7 @@
     Get a recommendation on tool vs. agent vs. workforce based on your use case.
   </Card>
   <Card title="Build and improve evals" icon="flask-vial" href="/build/agents/build-your-agent/evals">
     Diagnoses errored logs and tools, explains why a run failed, and proposes how to fix it — so you can build stronger evals.
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     When Inventor hits a platform issue it can't fix, it logs a bug to our engineering team on your behalf.
@@ -192,8 +192,31 @@
       </Step>
     </Steps>
   </Tab>
+  <Tab title="Panel size">
+    The Inventor panel can be expanded to fill the full workspace width, giving you more room when writing detailed prompts or reviewing Inventor's output.
+
+    **How to maximize the panel:**
+
+    - Click the **maximize** button in the Inventor panel header to expand it to full width. Click it again to return to the default size.
+    - Drag the resize handle on the left edge of the panel all the way to the left edge of the screen to maximize it.
+
+    When the panel is maximized, the main left navigation collapses automatically to free up the full screen width.
+
+    Navigating to a different page automatically returns the panel to its default (non-maximized) size.
+
+    **Sidebar nav on wider screens:**
+
+    When the panel is wide enough (1024px or wider), a sidebar nav appears inside the panel. It shows your past conversations and a new chat button — the same access you'd otherwise get from the **Chats** dropdown, but always visible in a persistent left rail within the panel.
+
+    <Note>
+      Screenshots of the maximized panel, the sidebar nav, and the maximize button in the header will be added here.
+    </Note>
+  </Tab>
   <Tab title="Conversations">
-    Inventor saves each conversation as a session automatically. Opening the panel starts a new chat, and your past sessions stay available from the **Chats** dropdown in the panel header — browse or search them, then select one to resume where you left off.
+    Inventor saves each conversation as a session automatically. Opening the panel starts a new chat. How you access past sessions depends on the panel width:
+
+    - **Default (narrow) panel:** Past sessions are available from the **Chats** dropdown in the panel header — browse or search them, then select one to resume where you left off.
+    - **Wide panel (1024px or wider):** A sidebar nav appears inside the panel showing your past conversations and a new chat button, replacing the header dropdown with a persistent left rail.
 
     <Info>
       Closing the panel or refreshing the page doesn't delete your conversation history — sessions persist and can be resumed at any time.