fix(qt): a submenu stays open while the pointer is over its rows

CardMenu's pair-hover check read the popup's HoverHandler, which lives on
the background and never fires over a row: the rows' MouseAreas take the
hover events, so the panel only counted as hovered on its 5px padding.
Crossing from that padding into the child's first row read as "left both
menus" and the 350 ms leave timer closed the pair — the Copy submenu
closed the whole context menu as soon as it was entered.

A menu is now hovered while its panel OR one of its rows is (one hot row
at a time, held by reference so a destroyed row cannot leave it stuck),
and the pair check reads that on both menus. scripts/test-card-menu-qml.sh
drives the pointer through the parent row, the child's rows, back to a
plain row and out, and joins the runtime gate and CI.

cc

scripts/qml-tests/tst_card_menu.qml

@@ -0,0 +1,81 @@
+// CardMenu submenus: hovering the child must keep BOTH menus open (the
+// rows' MouseAreas must count as menu hover), moving to a plain row in the
+// parent closes the child only, and leaving both closes both.
+import QtQuick
+import QtTest
+import "../../crates/qbz-qt/qml/controls"
+
+Item {
+    id: root
+    width: 700; height: 500
+
+    Item { id: anchorItem; x: 120; y: 80; width: 10; height: 10 }
+
+    CardMenu {
+        id: menu
+        entries: [
+            { "label": "One", "icon": "", "action": "one" },
+            { "label": "Copy", "icon": "", "action": "copy", "submenu": [
+                { "label": "Sub A", "icon": "", "action": "sub-a" },
+                { "label": "Sub B", "icon": "", "action": "sub-b" }
+            ] },
+            { "label": "Three", "icon": "", "action": "three" }
+        ]
+    }
+    SignalSpy { id: picks; target: menu; signalName: "picked" }
+
+    TestCase {
+        name: "CardMenuSubmenu"
+        when: windowShown
+        // Row i's centre inside a menu (5px padding, 33px rows).
+        function rowY(m, i) { return m.y + 5 + 33 * i + 16 }
+
+        function test_a_hover_keeps_the_pair_open() {
+            menu.openAtCursor(anchorItem, 0, 0)
+            wait(50)
+            verify(menu.opened)
+            mouseMove(root, menu.x + 40, rowY(menu, 1))
+            wait(120)
+            verify(menu.subOpen, "hovering the Copy row opens the child")
+            var sub = menu._sub
+            verify(sub.opened)
+            mouseMove(root, sub.x + 40, rowY(sub, 0))
+            wait(600)
+            verify(menu.opened, "the parent stays open while the child's first row is hovered")
+            verify(sub.opened, "the child stays open while its first row is hovered")
+            mouseMove(root, sub.x + 40, rowY(sub, 1))
+            wait(600)
+            verify(menu.opened && sub.opened, "still open on the child's second row")
+            // Back onto a plain parent row: the child goes away, the parent stays.
+            mouseMove(root, menu.x + 40, rowY(menu, 0))
+            wait(120)
+            verify(menu.opened)
+            verify(!menu.subOpen, "a plain row puts the child away")
+            // Leave both: both close.
+            mouseMove(root, menu.x + 40, rowY(menu, 1))
+            wait(120)
+            verify(menu.subOpen)
+            mouseMove(root, 650, 450)
+            wait(700)
+            verify(!menu.opened, "leaving both closes the parent")
+        }
+
+        function test_b_picking_in_the_child_closes_everything_and_forwards() {
+            picks.clear()
+            menu.openAtCursor(anchorItem, 0, 0)
+            wait(50)
+            mouseMove(root, menu.x + 40, rowY(menu, 1))
+            wait(120)
+            var sub = menu._sub
+            verify(sub && sub.opened)
+            mouseMove(root, sub.x + 40, rowY(sub, 1))
+            wait(100)
+            mouseClick(root, sub.x + 40, rowY(sub, 1))
+            wait(100)
+            compare(picks.count, 1)
+            compare(picks.signalArguments[0][0], "sub-b")
+            verify(!menu.opened)
+            verify(!sub.opened)
+        }
+    }
+}

scripts/qt-runtime-gate.sh

@@ -10,6 +10,7 @@ bash scripts/test-text-edit-menu-qml.sh
 bash scripts/test-compact-seek-qml.sh
 bash scripts/test-library-folders-qml.sh
 bash scripts/test-array-model-qml.sh
+bash scripts/test-card-menu-qml.sh
 bash scripts/test-orbit-qml.sh
 node scripts/test_qt_local_views.mjs
 node scripts/test_qt_library.mjs

scripts/test-card-menu-qml.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# CardMenu submenu regression: hovering the child keeps the pair open,
+# leaving both closes both, a pick in the child forwards and closes all.
+set -euo pipefail
+cd "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/.."
+if [[ -n "${QT_ROOT_DIR:-}" ]]; then
+  qt_card_menu_bins="$QT_ROOT_DIR/bin"
+else
+  qt_card_menu_qmake="${QMAKE:-}"
+  if [[ -z "$qt_card_menu_qmake" ]]; then
+    qt_card_menu_qmake="$(command -v qmake6 || command -v qmake)"
+  fi
+  qt_card_menu_bins="$("$qt_card_menu_qmake" -query QT_INSTALL_BINS)"
+fi
+QT_QPA_PLATFORM=offscreen QT_QUICK_BACKEND=software \
+  "$qt_card_menu_bins/qmltestrunner" \
+  -input scripts/qml-tests/tst_card_menu.qml \
+  -import scripts/qml-tests/imports