CLI Machines Workspace Split

`ed machines workspace split`

Splits a pane in two and points the new one at a machine and a screen.

Usage:

ed machines workspace split <pane> <machine> [--side <side>] [--screen <screen>]
                            [--workspace <workspace>] [--json]

Arguments:

Name	Type / values	Default	What it does
`<pane>`	integer, 1 to the pane count	required	Which pane to split, counting from 1 as `panes` numbers them.
`<machine>`	machine name, ssh alias, id or unambiguous prefix	required	What the new pane points at.

Options:

Name	Type / values	Default	What it does
`--side`	`left`, `right`, `top`, `bottom`	`right`	Which side of the existing pane the new one goes on. `left` and `right` split horizontally, `top` and `bottom` vertically.
`--screen`	`overview`, `processes`, `docker`, `terminal`, `files`, `tools`	`overview`	What the new pane shows.
`--workspace`	name, id, or unambiguous name prefix	the current workspace	Which workspace to split a pane in.
`--json`	flag	off	Emits one JSON document on stdout.

--json shape: the workspace after the split, in the shape panes prints. The new pane is the focused one.

Examples:

ed machines workspace split 1 mini
ed machines workspace split 1 mini --side bottom --screen terminal
ed machines workspace split 2 tuf --screen docker --workspace Fleet
ed machines workspace split 1 mini --json

$ ed machines workspace split 1 mini --side bottom --screen terminal
split pane 1 to the bottom; 3 panes now

Behaviour: this is the pane header's split menu, which offers Split Right and Split Down and reuses the pane's own target; ed reaches all four sides and makes you say what the new pane points at. The new pane carries exactly one tab, on the machine and screen you named, and becomes the focused pane. Where it lands depends on what is already there. If the pane you split already sits in a split running along the same axis, the newcomer joins as a sibling: it takes an equal share and every existing sibling is scaled down to make room, so three panes in a row stay a row rather than becoming a row containing a row. Otherwise the pane is replaced by a fresh split of the two, half and half.

--side left and --side top insert before the pane you named, which means the new pane takes that pane's number and everything after it shifts up by one. Read panes again rather than assuming the number you split is still the same pane.

Nothing is written until every argument checks out, and they are checked in this order: the pane number, the machine, the side, then the screen. A bad pane number exits 3 and says how many the workspace has; an unknown machine exits 3 with the known machines in the hint; a bad side or screen exits 3 and lists the accepted values:

$ ed machines workspace split 7 tuf
error: there is no pane 7 in Compare
hint: it has 2, numbered from 1

$ ed machines workspace split 1 tuf --side sideways
error: no side called sideways
hint: sides: left, right, top, bottom

There is no cap on the number of panes and no check that a screen suits the machine. --screen docker on a machine without Docker is accepted here and fails later, in the pane, where the app's own tab menu would simply not have offered it.