Fixes from three adversarial reviews, and a destructive one among them

The registry sweep could delete a live socket, anywhere on the filesystem. A
reviewer reproduced it: a socket that is bound but has not reached listen(2)
answers ECONNREFUSED exactly like a dead one -- that window is every server's
startup -- and the sweep then followed the entry's symlink and unlinked
whatever absolute path it named. It now follows a target only into the
directory our own sockets live in and only to a `pardes-9p-*.sock` name, it
re-probes immediately before deleting rather than trusting a probe that is by
then several syscalls old, and a readlink that exactly filled its buffer is
treated as the truncation it is. The test grew a case for an entry whose
target is not ours: the entry goes, the file does not.

Ctrl-V in raw tty mode was a black hole when the yank register was empty --
neither typed nor forwarded -- so vim's visual block, readline's quoted-insert
and every other program's Ctrl-V simply vanished. With nothing to paste the
chord belongs to the program again.

The lone-ESC flush added earlier was dead code. vaxis already returns Escape
for a one-byte 0x1b (`Parser.parseGround` asserts `input.len == 1`), so the
carried byte it waited for can never exist; a reviewer showed a 3 ms gap and a
60 ms gap behaving identically. Removed rather than left to imply a guarantee
it never provided.

A shell whose editor is gone can start one again. Naming a live but
unreachable session made `pardes <file>` exit 1, which let a stale environment
variable lock someone out of their own editor; it falls through to an ordinary
session, as it did before the variable existed.

Also: the macOS ABI check for `pardes_topbar_pane_border_px` had been replaced
by a duplicate of the line above it; `--startup` now fails on a leak the way
every other measurement in that file does, and stops calling its maximum a p95
below twenty samples; the served README and the skill no longer tell you to
write to `data` with `>`, which truncates the whole body before the write
lands; `docs/v9fs.md` described the allocate-on-walk design that was rejected;
and `test/fs.py` keys nesting off `PARDES_PID`, so its forwarding case stops
passing only when the runner happens to be inside a live pardes.

fs-test now reaches its one documented pre-existing failure instead of dying
early. Suite 778/783 with the two known crashes.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/fs-help.txt b/src/fs-help.txt
index 3113590a..7f55b3af 100644
--- a/src/fs-help.txt
+++ b/src/fs-help.txt
@@ -23,7 +23,7 @@ Below, $m is the mount point (PARDES_MOUNT in a Tty9p shell; 9ns and 9p work too
   cat $m/pane/$n/name; echo notes.txt > $m/pane/$n/name        read, then rename
   echo Save > $m/pane/$n/exec                  save it; rmdir $m/pane/$n closes it
   echo 'Msg hello' > $m/exec                   show text in the editor
-  echo '#0,#5' > $m/pane/$n/addr; echo NEW > $m/pane/$n/data   replace bytes 0..5
+  echo '#0,#5' > $m/pane/$n/addr; printf NEW >> $m/pane/$n/data  replace bytes 0..5
   cp $m/pane/$n/addr $m/pane/$n/dot; cat $m/pane/$n/sel   select the range, read it
   cat $m/pane/$n/dirty; echo 0 > $m/pane/$n/dirty         is it modified? say it is not
   cat $m/log                                   block until a pane is made, renamed, saved or closed