Commit git hooks

Use the [Githooks] convention for storing git hooks in the repository.
Add commit hooks to check for ASCII filenames and whitespace errors
(from the git sample hook) and for running ruff checks.

[Githooks]: https://github.com/rycus86/githooks

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

Author: kevinoid

.githooks/pre-commit/10-nonascii-and-whitespace.sh

@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+# Enforce hooks.allownonascii and core.whitespace configuration on commit.
+#
+# Copied from:
+# https://github.com/git/git/blob/v2.18.0/templates/hooks--pre-commit.sample
+
+if git rev-parse --verify HEAD >/dev/null 2>&1
+then
+	against=HEAD
+else
+	# Initial commit: diff against an empty tree object
+	against=$(git hash-object -t tree /dev/null)
+fi
+
+# If you want to allow non-ASCII filenames set this variable to true.
+allownonascii=$(git config --bool hooks.allownonascii)
+
+# Redirect output to stderr.
+exec 1>&2
+
+# Cross platform projects tend to avoid non-ASCII filenames; prevent
+# them from being added to the repository. We exploit the fact that the
+# printable range starts at the space character and ends with tilde.
+if [ "$allownonascii" != "true" ] &&
+	# Note that the use of brackets around a tr range is ok here, (it's
+	# even required, for portability to Solaris 10's /usr/bin/tr), since
+	# the square bracket bytes happen to fall in the designated range.
+	test $(git diff --cached --name-only --diff-filter=A -z $against |
+	  LC_ALL=C tr -d '[ -~]\0' | wc -c) != 0
+then
+	cat <<\EOF
+Error: Attempt to add a non-ASCII file name.
+
+This can cause problems if you want to work with people on other platforms.
+
+To be portable it is advisable to rename the file.
+
+If you know what you are doing you can disable this check using:
+
+  git config hooks.allownonascii true
+EOF
+	exit 1
+fi
+
+# If there are whitespace errors, print the offending file names and fail.
+exec git diff-index --check --cached $against --

.githooks/pre-commit/20-ruff.sh

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+#!/bin/sh
+# Run ruff check (and format --check) on changed .py and .pyi files
+
+set -Ceu
+
+# Ensure ruff is available.
+# Could use tox/venv, but they are too heavy/slow for my tastes
+if ! command -v ruff >/dev/null ; then
+	# shellcheck disable=SC2016
+	echo 'Warning: ruff not on $PATH.  Skipping pre-commit check.' >&2
+	exit 0
+fi
+
+git diff -z --cached --name-only --diff-filter=AM -- '*.py' '*.pyi' |
+	xargs -0r ruff check --
+
+git diff -z --cached --name-only --diff-filter=AM -- '*.py' '*.pyi' |
+	xargs -0r ruff format --check --diff --