embed mode: hide header breadcrumb + right actions, show only editor

- Hide .unified-header and .header-actions in embed-mode (not just .topbar)
- Hide .topbar-right specifically (Edited, Share, Copy link, Favorite, ...)
- Set .page-editor-wrapper padding-top to 12px (no header gap)
- Only the document editor/content is visible in the iframe now

app/templates/base.html

@@ -88,11 +88,12 @@
         font-size: 13px;
       }
     }
-    /* Embed mode — hide sidebar + topbar for peek panels */
-    body.embed-mode .sidebar, body.embed-mode .topbar, body.embed-mode .app-layout { display: block !important; }
+    /* Embed mode — hide sidebar + header for peek panels */
     body.embed-mode .sidebar { display: none !important; }
-    body.embed-mode .topbar { display: none !important; }
+    body.embed-mode .topbar, body.embed-mode .unified-header { display: none !important; }
+    body.embed-mode .topbar-right, body.embed-mode .header-actions { display: none !important; }
     body.embed-mode .app-layout { margin-left: 0 !important; padding-top: 0 !important; }
+    body.embed-mode .page-editor-wrapper { padding-top: 12px !important; }
     body.embed-mode .sidebar-collapsed .app-layout { margin-left: 0 !important; }
   </style>
   <script src="/static/js/htmx.min.js"></script>