The full-screen overlay window sets `window { background-color: transparent }`
in its app CSS (APPLICATION priority), but `bind_window_auto` re-broadcasts
the shared component sheet — which includes `window { background-color: @bg }`
— as a widget-tree provider at STYLE_PROVIDER_PRIORITY_USER - 10. Provider
priority is the primary cascade key, so that outranks the app rule regardless
of selector specificity: the "transparent overlay" fills the screen with an
opaque @bg (#0c0c0c) rectangle, hiding the whole desktop behind the launcher.
Guaranteed to bite under a VM's software renderer where there's no GL context
to paper over it.
Bind the app sheet too, via bind_window_auto_with_app_css (rides at USER - 9,
back above the shared window rule) — same pattern breadbar and breadhelp
already use. Verified with a headless pixman sway + solid-colour background:
the overlay region outside the panel now shows the desktop through.
breadsearch and breadclip use the same new_overlay_window + bind_window_auto
pattern and need the same fix.
