make model section open by default and fix headerModelButton reference cleanup

public/app/dom.js

@@ -8,7 +8,6 @@ const messagesDiv = $("messages");
 const modelSelect = $("model");
 const modelPanel = $("modelPanel");
 const modelBadgeName = $("modelBadgeName");
-const headerModelButton = $("headerModelButton");
 const headerModelName = $("headerModelName");
 const headerPersonaName = $("headerPersonaName");
 const modelCount = $("modelCount");
@@ -164,7 +163,6 @@ export {
     logoutButton,
     messagesDiv,
     modelBadgeName,
-    headerModelButton,
     headerModelName,
     headerPersonaName,
     modelCount,

public/index.html

@@ -138,7 +138,7 @@
                                                 <span id="chatUserPersonaPill" class="context-pill hidden">User persona: none</span>
                                             </div>
                                         </div>
-                                        <details class="chat-drawer-section chat-drawer-disclosure chat-drawer-section--model">
+                                        <details class="chat-drawer-section chat-drawer-disclosure chat-drawer-section--model" open>
                                             <summary class="chat-drawer-row">
                                                 <span class="chat-drawer-row-label">
                                                     <span class="eyebrow">AI model</span>
@@ -424,6 +424,6 @@
 
 <script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js" defer></script>
 <script src="https://cdn.jsdelivr.net/npm/dompurify@3.0.6/dist/purify.min.js" defer></script>
-<script type="module" src="script.js"></script>
+<script type="module" src="script.js?v=20260908-model-controls"></script>
 </body>
 </html>

public/script.js

@@ -35,7 +35,6 @@ import {
     manageChatMemoryBtn,
     managePersonaStateBtn,
     importWorkspaceFileInput,
-    headerModelButton,
     headerModelName,
     headerPersonaName,
     moveChatFolderBtn,
@@ -117,6 +116,8 @@ import {
     userPersonaList
 } from "./app/dom.js";
 
+const headerModelButton = document.getElementById("headerModelButton");
+
 let isProcessing = false, activeChatId = null, editingPersonaId = null, editingPersonaType = "assistant", currentUsername = "";
 let chatSessions = [], currentMessages = [], assistantPersonas = [], userPersonas = [];
 let activeUserPersonaId = null, currentSummary = null, publishedPersonaIds = new Set();