fix: isolate chat button from fixed-btn stack to ensure right position

- Move chat-widget outside the floating buttons section in index.html
- Remove fixed-btn class from toggle button (was inheriting left-side
  positioning from the button stack's mobile flex layout)
- Chat widget now renders independently just before body-scripts

templates/index.html

@@ -50,7 +50,6 @@
     {{template "contact-button" .}}
     {{template "zoom-toggle-button" .}}
     {{template "shortcuts-button" .}}
-    {{template "chat-widget" .}}
 
     <!-- ============================================ -->
     <!-- MODALS                                      -->
@@ -62,6 +61,11 @@
     {{template "contact-modal" .}}
     {{template "zoom-control" .}}
 
+    <!-- ============================================ -->
+    <!-- CV ASSISTANT (independent of button stack)  -->
+    <!-- ============================================ -->
+    {{template "chat-widget" .}}
+
     <!-- ============================================ -->
     <!-- SCRIPTS & ANALYTICS                         -->
     <!-- ============================================ -->