Introduce a declarative KWin script that maintains a binary-space
partition layout per output for normal windows in convergence mode.
New windows are added to the active screen and the layout is
recomputed with 8 px outer and 8 px inner gaps; closed windows are
removed and neighbours expand to fill the freed area.
Windows that fail isTileable (panels, fixed-size dialogs, fullscreen,
xwaylandvideobridge, manually-floated) are left untouched. A 200 ms
deferred-retile timer mirrors the convergentwindows pattern so the
dockSpaceReserver layer-shell exclusive zone is settled before
clientArea is queried.
Dragging a tile and dropping it onto another tile swaps the two slots
in the BSP layout; an outline is drawn on the hovered target as a
visual cue. Drops elsewhere snap the tile back to its original slot
and leave KWin native quick-tile and electric borders untouched.
Keyboard bindings:
Meta+H/J/K/L focus left/down/up/right
Meta+F toggle float on the active window
Meta+T toggle tiling globally
