Review everything shipped this weekend, and fix what the reviewers caught

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8

config/dot/quickshell/modules/settings/DisplayArrangement.qml

@@ -12,6 +12,7 @@
 // mirroring, rather than drawing it wherever its stale coordinates point.
 
 import QtQuick
+import Quickshell
 import qs.config
 import qs.widgets
 import "../../services/DisplayLayout.js" as DisplayLayout
@@ -198,7 +199,20 @@ Item {
             }
 
             Repeater {
-                model: root.tiles
+                // Keyed on the output name rather than fed the array directly.
+                // Every drag step and every arrow key rewrites draftLayout,
+                // which rebuilds `tiles` into a fresh array of fresh objects --
+                // a new model, which resets the Repeater and destroys the tile
+                // being dragged on its first millimetre of travel. The drag
+                // ended there, silently, and nothing was ever applied; the
+                // arrow keys lost focus after a single step for the same
+                // reason. Keyed, the same rebuild is "this row moved", and the
+                // tile under the pointer keeps its handler and its focus.
+                model: ScriptModel {
+                    values: root.tiles
+                    objectProp: "name"
+                    comparisonMode: ObjectComparison.Structure
+                }
 
                 Rectangle {
                     id: tile