Drop chmod from setup; hook ships executable

.githooks/commit-msg

@@ -9,10 +9,10 @@
 # Enable after cloning:
 #
 #     git config core.hooksPath .githooks
-#     chmod +x .githooks/commit-msg
 #
-# The Gitea web API cannot set the executable bit, so the chmod is required
-# on first clone even though the file is committed.
+# The executable bit is committed (mode 100755), so a clone gets a runnable
+# hook. Git still will not enable a repo's hooks on its own — deliberately, so
+# that cloning cannot execute code from the remote — hence the one command.
 
 msg_file="$1"
 

README.md

@@ -139,5 +139,6 @@ Nothing about the format is bot-specific. Fetch the JSON and use it however you
 ## Note on history
 
 Commits here carry no AI attribution — see [`.githooks/commit-msg`](.githooks/commit-msg),
-enabled with `git config core.hooksPath .githooks && chmod +x .githooks/commit-msg`.
-Please keep it that way in PRs.
+enabled with `git config core.hooksPath .githooks` after cloning. The hook ships
+executable; Git just never turns a repo's hooks on by itself. Please keep it that
+way in PRs.