The notification menu learns what every other popover already knew

Popover's container is a plain Item and never measures its children, so
the three-dots menu on a notification card opened as a 240x28 sliver
with its one row clipped out of existence. TrayMenu and AgentUsagePanel
both carry the antidote — implicit sizes on the Popover itself, taken
from the content column — and now the notification settings menu does
too, with rows filling the window width so the hover reaches the edges.

Claude-Session: https://claude.ai/code/session_01W8icivxZcmFTR2g6DkYhjT

config/dot/quickshell/modules/notifications/NotificationCard.qml

@@ -177,12 +177,20 @@ Rectangle {
         id: settingsMenu
         anchorItem: settingsMenuButton
 
-        // A Column already measures itself from its children, and in Qt 6 both
-        // implicit sizes are read-only on a positioner -- assigning them makes
-        // the whole shell fail to load rather than just this menu.
+        // Popover's container is a plain Item and does not size itself from its
+        // children, so the window dimensions come from the column's implicit
+        // size — the same pattern TrayMenu uses. Rows take their *actual* width
+        // from the window in the other direction; the two chains are
+        // independent, so there is no binding loop.
+        implicitWidth: Math.max(menuBody.implicitWidth + contentPadding * 2, 200)
+        implicitHeight: menuBody.implicitHeight + contentPadding * 2
+
         Column {
+            id: menuBody
+            width: parent.width
+
             TrayMenuRow {
-                id: notificationSettings
+                width: parent.width
                 label: "Notification settings"
                 onActivated: {
                     ShellState.openSettings("notifications");