feat: Finish migration, b=no-bug, c=no-component

prefs/zen/view.yaml

@@ -40,12 +40,6 @@
 - name: zen.view.window.scheme
   value: 2
 
-- name: zen.view.drag-and-drop.move-over-threshold
-  value: 70
-
-- name: zen.view.drag-and-drop.edge-zone-threshold
-  value: 25
-
 - name: zen.view.context-menu.refresh
   value: '@IS_TWILIGHT@'
 

prefs/zen/zen.yaml

@@ -20,6 +20,12 @@
 - name: zen.tabs.close-window-with-empty
   value: true
 
+- name: zen.tabs.use-legacy-drag-and-drop
+  value: false
+
+- name: zen.tabs.folder-dragover-threshold-percent
+  value: 20 # Percentage of folder height to trigger dragover
+
 - name: zen.ctrlTab.show-pending-tabs
   value: false
 

src/browser/base/content/zen-assets.jar.inc.mn

@@ -4,6 +4,7 @@
 
 #include ../../../zen/common/jar.inc.mn
 #include ../../../zen/compact-mode/jar.inc.mn
+#include ../../../zen/drag-and-drop/jar.inc.mn
 #include ../../../zen/split-view/jar.inc.mn
 #include ../../../zen/mods/jar.inc.mn
 #include ../../../zen/workspaces/jar.inc.mn

src/zen/drag-and-drop/ZenDragAndDrop.js

@@ -542,6 +542,12 @@
     }
 
     handle_drop_transition(dropElement, draggedTab, movingTabs, dropBefore) {
+      if (isTabGroupLabel(dropElement)) {
+        dropElement = dropElement.group;
+      }
+      if (isTabGroupLabel(draggedTab)) {
+        draggedTab = draggedTab.group;
+      }
       if (
         gReduceMotion ||
         dropElement.group !== draggedTab.group ||