sl0p: serialise the pane status bar for resurrection

The status bar survived detach/reattach (it lives on Grid) but not a
serialise/restore cycle, so a resurrected pane came back blank.

It now travels the whole per-pane serialisation pipeline, mirroring the fork's
existing default_fg/default_bg: pane -> PaneLayoutMetadata ->
PaneLayoutManifest -> TiledPaneLayout -> a status_bar property in the serialised
KDL, then back through the normal layout parser and applied by LayoutApplier
when the pane is recreated.

The sanitiser moved from grid.rs into zellij-utils so both entry points share
one definition. That matters: a layout file on disk is no more trustworthy than
the escape sequence that wrote it -- it may have been hand-edited, or copied from
somewhere else -- so restored text is stripped and length-capped on the way in
just like the OSC payload was.

Verified end to end rather than by unit test alone: set the bar, waited for a
serialisation pass, confirmed status_bar="..." in session-layout.kdl, killed the
session until list-sessions reported EXITED, then attached and watched it come
back from disk. The earlier attempt only proved detach/reattach because Quit had
left the session alive.

1 files changed, 1 insertions, 23 deletions

diff --git a/zellij-server/src/panes/grid.rs b/zellij-server/src/panes/grid.rs
index da937456..b91fa2a7 100644
--- a/zellij-server/src/panes/grid.rs
+++ b/zellij-server/src/panes/grid.rs
@@ -408,28 +408,6 @@ fn subtract_isize_from_usize(u: usize, i: isize) -> usize {
     }
 }
 
-/// Longest status bar text we keep. A pane can only ever show one row of it, and
-/// the string is held for the life of the pane, so there is no reason to retain
-/// megabytes because a program looped.
-const MAX_STATUS_BAR_TEXT: usize = 512;
-
-/// Make program-supplied status text safe to draw.
-///
-/// The payload arrives in-band from whatever is running in the pane -- which
-/// includes `cat` of a file someone else wrote -- so it is untrusted. Control
-/// characters are dropped rather than escaped: a stray ESC would let the payload
-/// break out of the frame row and repaint anything it liked, and a newline or
-/// carriage return would corrupt the row. Truncation is by characters, not bytes,
-/// so it cannot split a multi-byte one.
-pub fn sanitize_status_bar_text(raw: &str) -> String {
-    raw.chars()
-        .filter(|c| !c.is_control())
-        .take(MAX_STATUS_BAR_TEXT)
-        .collect::<String>()
-        .trim()
-        .to_owned()
-}
-
 pub fn parse_osc7_path(raw: &[u8]) -> Option<std::path::PathBuf> {
     let s = std::str::from_utf8(raw).ok()?;
     let rest = s.strip_prefix("file://")?;
@@ -4152,7 +4130,7 @@ impl Perform for Grid {
                             .flat_map(|p| str::from_utf8(p))
                             .collect::<Vec<&str>>()
                             .join(";");
-                        let text = sanitize_status_bar_text(&text);
+                        let text = zellij_utils::input::layout::sanitize_status_bar_text(&text);
                         self.status_bar = if text.is_empty() { None } else { Some(text) };
                     },
                     Some(b"clear") => {