Make a pane's tag a Text edited with the body's own keys

The tag was a fixed buffer with its own one-line editor, a cursor measured
across the path, and a hijack of the body's mode while it was typed into.
It is now the pane's second Text: its own characters after the computed
prefix (path, dirty marker, PDF page), which is never stored in it, so a
rename or a dirty marker never moves its cursor. Normal and insert mode are
the body's, undo included; `:` moves the keyboard between body and tag, the
tag remembers its cursor and starts on Save, and executing a word from it
hands the keyboard back. The mouse still sees the prefix: a sweep selects
across it and a click on the path drafts a new name.

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

1 files changed, 10 insertions, 10 deletions

diff --git a/test/snapshots/tagcmd.snap b/test/snapshots/tagcmd.snap
index 305ed521..0e9047fb 100644
--- a/test/snapshots/tagcmd.snap
+++ b/test/snapshots/tagcmd.snap
@@ -1,11 +1,12 @@
 # `:` — vim's command line with acme's vocabulary. It focuses the pane's OWN
 # tag in NORMAL mode (block cursor; the layout box shows the pane's BODY mode,
-# which for this file pane is normal either way), parked at the tail's
-# START — always the start, so `:w` is the same two keystrokes every time.
-# Motions walk the tag's words (w selects the "Save" span, exactly like a body
-# word motion), the execute chord runs the one under the cursor and hands the
-# body back in normal mode — same keys as the body, so Tab by default (see
-# config.look_key/exec_key). Esc backs out instead, leaving the tail as it was.
+# which for this file pane is normal either way). The tag remembers where its
+# cursor was; the first time there is nothing to remember and it starts on
+# Save. The tag's normal mode is the body's: w selects the "Save" span exactly
+# as a body word motion does, and the execute key runs the word under the
+# cursor and hands the body back — same keys as the body, so Tab by default
+# (see config.look_key/exec_key). `:` again backs out instead, leaving the tag
+# as it was.
 lines c.txt 6
 start 31 100 c.txt
 wait 8000 Newcol Joincol
@@ -18,7 +19,7 @@ key esc
 settle 100
 stable 400 5000
 snap edited
-# `:` -> the tag, in normal mode, cursor on the tail's first cell
+# `:` -> the tag, in normal mode, cursor on Save
 key :
 stable 400 5000
 snap colon
@@ -32,10 +33,9 @@ stable 600 8000
 stable 400 5000
 snap saved
 snapfile written /tmp/pardes-snap/tagcmd/cwd/c.txt
-# `:` then Esc: back to the body with the tail untouched, nothing run
+# `:` then `:`: back to the body with the tag untouched, nothing run
 key :
 stable 400 5000
-key esc
-settle 100
+key :
 stable 400 5000
 snap escaped