[SuceV587]

ListenFree’s normal and now-playing headers drew private traffic lights and never registered control positions with KWin. Both headers now share one optional native protocol slot for their surface. Only client button children hide after acknowledgement; the geometry target stays opaque, and unsupported desktops retain functional controls. The green button means maximize/restore, matching the protocol; F11 and the separate player fullscreen action remain available.

Validation at 34d7be5a6ce595cf86571a6749e48bf88ef112d9:

• Both push/PR native CI builds passed, including installer regressions and the new single-slot/header-switch regression. The first fixture-visibility failure was corrected and rerun successfully.
• The exact installed CI candidate was run in the designated Ubuntu 26.04 VM under isolated KWin, with an empty profile and network disabled. Both home and nowplaying captures required actual compositor takeover and exited successfully. Protocol inspection found exactly one control object per window. Paired client/compositor screenshots were inspected locally.
• Native review exports now reject missing protocol/takeover when LISTENFREE_REVIEW_REQUIRE_COMPOSITOR_CONTROLS=1 is set.

This repository currently publishes source releases, not Flatpak bundles. Native acceptance does not claim that a Flatpak is available. Existing application data and real accounts were not accessed.