A builtin's Verbose announcement is logged only when it succeeds

A failure said while it ran (Exit's refusal, a Del refused) or later by
the host (a Save's write, a Dump's) left `msg N Save` in the log as if it
had worked. The announcement's record is remembered and taken back out
on either, unless a follower read it already. A refused pane/new logs its
err alone, and a failed Dump says its reason in words (`file not found`,
not `FileNotFound`) so its msg goes and the err is the one record.

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

1 files changed, 7 insertions, 4 deletions

diff --git a/docs/fs.md b/docs/fs.md
index e7c85681..ffee9124 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -720,10 +720,13 @@ mapping the serial it had to the one it has now, and `restoredcol <old>
 for every line the editor says (with `verbose` on, that includes each
 builtin announcing itself as it runs, on purpose: the log says which ran --
 unless the builtin then says something of its own that starts with its
-name, `Kill: nothing running`, which takes the announcement's place; a
-builtin that fails its write (`ctl`, `exec`, `/tagexec` or a column's
-`exec`) is logged by that write's `err` alone, no announcement and no `msg`, so the same failure again is the same record
-again; a line said again word for word is counted, `msg 3 Undo: nothing to
+name, `Kill: nothing running`, which takes the announcement's place; an
+announcement is logged only for a builtin that succeeds: one that fails,
+as it runs or when the host could not do its work (a Save's write, a
+Dump's), leaves none, from a click at the keyboard too. A builtin that
+fails its write (`ctl`, `exec`, `/tagexec` or a column's `exec`, and an
+open of `pane/new`) is logged by that write's `err` alone, no announcement
+and no `msg`, so the same failure again is the same record again; a line said again word for word is counted, `msg 3 Undo: nothing to
 undo (x40)`, as `err` is (below); a text past 256 bytes is cut there,
 between words, and ends in an ellipsis, `…`, as an `err`'s reason is past
 200; its serial is the pane it ran at, `-` when the keyboard was on a