Every tab is maximized and kick draws no frames, so new toplevels
are pinned to client-side mode (headerbars keep working) and later
server-side requests are ignored. Pinning happens at map -- set_mode
asserts on a never-committed surface, and decoration-before-commit is
the normal order (calling it in new_toplevel_decoration aborts
wlroots); late binds pin immediately when already initialized.
Adds an xdeco probe (maps one shm-backed toplevel, reports the
configured mode) with a regression test asserting mode=1, tracks it
in build.sh staleness, and covers the global in protocol_globals.
Full suite: 153 passed, 2 skipped.
Andrew Hamilton
6b4418ae4f