docs: through a mount a malformed write is EINVAL and one that fails is EIO, and the error words keep it so

The served README said every refused write reads as EINVAL, but a mount's
errno is 9ns's reading of the error's words, so a no-match or out-of-range
address and a refused Exit came back EIO, as the dogfood run saw. That split
is the useful one, malformed against failed, so the docs now state it rather
than the words being bent to EINVAL; a test pins each error's words to its
side of it. It caught one: 'regular expression search took too long' read as
ENAMETOOLONG, and now says it gave up past its step budget.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/.agents/skills/pardes-9p/SKILL.md b/.agents/skills/pardes-9p/SKILL.md
index 49db81b9..9b751a26 100644
--- a/.agents/skills/pardes-9p/SKILL.md
+++ b/.agents/skills/pardes-9p/SKILL.md
@@ -154,7 +154,7 @@ selection, `/re/` searches on from its end and wraps unless `limit` is set,
 `?re?` or `-/re/` searches back, `#100,#50` fails `addresses out of order`,
 and a search that backtracks
 past a step budget (about 300 ms) fails with `regular expression search
-took too long`. A failed address says
+gave up, ...`. A failed address says
 why (`no match for regexp`, `address out of range`) and leaves no address:
 `data` refuses until the next good one, so a missed target is never
 written at the old one. Moving `dot` scrolls the pane to it. `limit` bounds a