File the tag code into tagline.zig and draw tags beside bodies

With tags reduced to Texts, what is left of them is the computed prefix, the
default and saved tails, entering and leaving a tag and the headers: that goes
to tagline.zig, as acme keeps the tag half of a window in wind.c. Tag and
header drawing moves next to body drawing in body_layer.zig, and the tag hit
helpers go to tag_layer.zig with the Hit they read, where sameCell now also
tells the lines of a taller tag apart. The docs describe the tag as a Text.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/src/fs-help.txt b/src/fs-help.txt
index 4eecad41..efdecf46 100644
--- a/src/fs-help.txt
+++ b/src/fs-help.txt
@@ -39,7 +39,7 @@ Pitfalls, one each:
   addr, dot and limit read the same pair of offsets they take, so cp between them works.
   dirty, mark and scroll read "0" or "1" and take "0" or "1"; truncating limit lifts it.
   Writing body appends; open it with truncation to replace; writes are whole UTF-8 sequences.
-  Truncating tag clears the part you may edit; truncating dot or addr empties it.
+  tag reads path++text; writes append to the text (newlines too); truncating clears it, and dot or addr.
   A terminal's body is a history snapshot frozen per open; pty/data is the live stream.
   A failing command is reported in the editor and in log, not as a write error; a bad line fails the write.
   pane/<n>/ctl: acme's status line; takes get (reload), lock/unlock on a held fd (exec 3>ctl; echo lock >&3).