1. Open an OOUI modal (e.g. the help dialog in VE, Ctrl+?)
2. Trigger a notification: `mw.notify('test')`
3. Observed: The notification appears beneath the translucent overlay and the dialog
3. Expected: The notification appears above the translucent overlay and the dialog
In core the notifications overlay has a z-index of 10,000 (which puts it above OOUI modal's 101 and MMV's 1,001 (see T312778), but there is a rule `.vector-sticky-header-enabled .mw-notification-area` which resets it to z-index of 3.
This rule is applied in Vector classic too due to T312782.
# QA steps
1) log in
2) Scroll down the page so sticky header shows
3) Open the user menu
4) Click the watchstar
Expected: notification appears ABOVE user menu
# Previous QA steps
Originally the issue was raised with QA steps which no longer apply from what I can see:
1. Open an OOUI modal (e.g. the help dialog in VE, Ctrl+?)
2. Trigger a notification: `mw.notify('test')`
3. Observed: The notification appears beneath the translucent overlay and the dialog
3. Expected: The notification appears above the translucent overlay and the dialog