slosh: rename the project from sl0ppty

sl0p + pty was error-prone to type and the zero made it worse; slosh
(slop + sh) is one syllable, impossible to typo, and slosh.foo is ours.

Mechanical rename everywhere it appears: binary, env vars (SLOSH,
SLOSH_SESSION, SLOSH_BIN, SLOSH_CONFIG), socket dir (/tmp/slosh-<uid>,
$XDG_RUNTIME_DIR/slosh), config path (~/.config/slosh), header guards,
src/sl0ppty.h -> src/slosh.h, contrib/sl0ppty-dev -> contrib/slosh-dev,
the driving-slosh skill, docs and tests. The sl0ppi fork references and
the sl0p theme stay: one is history, the other is the brand.

The rename surfaced a latent bug in test_osc5577: the hello-reply
answer always appeared on screen twice (ECHOCTL echo plus cat -v), but
a seven-character implementation name happened to wrap the second copy
across the 60-column boundary, so counting substrings in wrapped text
found one and passed for the wrong reason. A five-character name moved
the wrap and exposed it. The loop guard itself is correct -- with echo
off before the request there is exactly one reply -- so the test now
counts on de-wrapped text and tolerates the pane's own echo.

1 files changed, 1 insertions, 1 deletions

diff --git a/docs/design.md b/docs/design.md
index 7da7d60..ce749d2 100644
--- a/docs/design.md
+++ b/docs/design.md
@@ -23,7 +23,7 @@ special case of anything.
 
 ## It runs headless
 
-`sl0ppty --script` is the whole thing without a terminal: commands in, the
+`slosh --script` is the whole thing without a terminal: commands in, the
 composited screen out as JSON. The interactive client and the test suite drive
 the same object through the same commands, so there is exactly one implementation
 of what a key does.