Move body drawing out of pardes.zig into body_layer.zig

Pure move, no behaviour change: renderBody, renderBodyLayer,
paintPointerSelection, paintSourceSelection, paintTerminalSelection and
bodyText go verbatim to the end of body_layer.zig, which already held the
body's layer geometry and hit-testing, so the pane body as the surface shows
it is one file. The file doc now says so.

The methods become free functions taking `p: *Pardes`; their 16 call sites
(render and renderPane, the tag painter, selection and dump code) change
from `p.renderBody(..)` to `body_layer.renderBody(p, ..)`. pardes.zig gains
`pub const body_layer = @import("body_layer.zig");`; pointerSourceLine,
selRegexArmed and cellBounds become pub because the moved code calls them.

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

0 files changed, 0 insertions, 0 deletions