One major todo is moving splits across different split trees (i.e.
moving across tabs and windows), but that would involve a lot more logic.
This MVP version works for now.
GTK version of #10090Closes#10224
Fixes#8406
Spatial split navigation now wraps at the edges.
We first attempt the nearest spatial target using the existing slot geometry.
If there is no candidate in the requested direction, we synthesize a wrapped
target by shifting the current slot by one full grid in the opposite
direction and reuse the same nearest-distance logic.
This fake target works because the grid is 1x1, so by moving it a full
grid size in the opposite direction, we effectively wrap around to the
other side of the grid.
When a tab contains only a single split, resize_split and toggle_split_zoom
actions now return false (not performed). This allows keybindings marked with
`performable: true` to pass the event through to the terminal program.
The performable flag causes unperformed actions to be treated as if the
binding didn't exist, so the key event is sent to the terminal instead of
being consumed.
- Add isSplit() helper to SplitTree to detect single-pane vs split state
- Update GTK resizeSplit/toggleSplitZoom to return false when single pane
- Update macOS resizeSplit/toggleSplitZoom to return Bool and check isSplit
- Add unit test for isSplit method
