Move the pipe's editor side out of pardes.zig into selection_pipe.zig

Pure move, no behaviour change: submitPipe, pipeRequest, pipeFailed,
pipeCut, pipeOutput and pipeResponse, the PendingPipe they share,
pipeMarker, and the eight pipe tests with their nextPipeEffect helper go
verbatim to the end of selection_pipe.zig, so the whole of `|` (runner,
boundary values, prompt, request and atomic edit) is one file. Inside that
file the `selection_pipe.` prefix drops; the file doc now says it holds both
halves.

The methods become free functions taking `p: *Pardes`: the four shells'
`core.pipeRequest(id)` become `selection_pipe.pipeRequest(core, id)`, and
pardes.zig's two calls change the same way. pushUndo becomes pub because
the pipe's edit calls it; PendingPipe.deinit becomes pub for Pardes.deinit.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

0 files changed, 0 insertions, 0 deletions