Add primary tile promotion

kwin/scripts/shift-tiling/contents/ui/main.qml

@@ -647,6 +647,34 @@ Item {
         }
     }
 
+    function promoteWindow(win) {
+        if (!isTileable(win)) return;
+
+        const outputName = screenNameForWindow(win) || (win.output ? win.output.name : "");
+        if (!outputName) return;
+
+        const key = windowKey(win);
+        const windows = orderedWindowsForScreen(outputName);
+        if (!key || windows.length < 2) return;
+
+        const reordered = [];
+        let promoted = null;
+        for (let i = 0; i < windows.length; i++) {
+            if (windowKey(windows[i]) === key) {
+                promoted = windows[i];
+            } else {
+                reordered.push(windows[i]);
+            }
+        }
+
+        if (!promoted) return;
+        reordered.unshift(promoted);
+        setStableLayout(outputName, reordered);
+        retileScreen(outputName);
+        scheduleRetile(outputName);
+        KWinComponents.Workspace.activeWindow = win;
+    }
+
     // ── Keyboard navigation helpers ──────────────────────────────────────────
 
     function centreOf(rect) {
@@ -1044,6 +1072,16 @@ Item {
         }
     }
 
+    KWinComponents.ShortcutHandler {
+        name: "SHIFT Tiling Promote Primary"
+        text: "SHIFT Tiling: Promote active window to primary tile"
+        sequence: "Meta+Shift+Return"
+        onActivated: {
+            const win = KWinComponents.Workspace.activeWindow;
+            if (win) root.promoteWindow(win);
+        }
+    }
+
     // Tiling on/off
     KWinComponents.ShortcutHandler {
         name: "SHIFT Tiling Toggle"

tests/check-dynamic-tiles-motion.sh

@@ -67,6 +67,10 @@ require_line "$tiling_script" "setStableLayout(outputName, remaining)"
 require_line "$tiling_script" "retileScreen(name)"
 require_line "$tiling_script" "retileScreen(targetName)"
 require_line "$tiling_script" "if (Math.abs(fromCenterX) < insertIntentDeadZone && Math.abs(fromCenterY) < insertIntentDeadZone)"
+require_line "$tiling_script" "function promoteWindow(win)"
+require_line "$tiling_script" "setStableLayout(outputName, reordered)"
+require_line "$tiling_script" "name: \"SHIFT Tiling Promote Primary\""
+require_line "$tiling_script" "sequence: \"Meta+Shift+Return\""
 
 reject_line "$tiling_script" "targetKey = lastLeafKey(rootNode)"
 reject_line "$tiling_script" "setScreenLayout(outputName, splitLeaf(rootNode, targetKey"