lint

feat(lsp): add canonical n6-lsp server (stdio JSON-RPC) #10

	name: lint

	on:
	push:
	branches: [main]
	pull_request:
	branches: [main]

	jobs:
	byte-canonical:
	name: Byte-canonical invariants
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4

	- name: Check UTF-8 validity
	run: \|
	set -e
	fail=0
	for f in examples/*.n6; do
	if ! iconv -f UTF-8 -t UTF-8 "$f" >/dev/null 2>&1; then
	echo "::error file=$f::not valid UTF-8"
	fail=1
	fi
	done
	exit $fail

	- name: Check no BOM
	run: \|
	set -e
	fail=0
	for f in examples/*.n6; do
	if head -c 3 "$f" \| od -An -tx1 \| grep -q 'ef bb bf'; then
	echo "::error file=$f::BOM present"
	fail=1
	fi
	done
	exit $fail

	- name: Check LF line endings only
	run: \|
	set -e
	fail=0
	for f in examples/*.n6; do
	if grep -lU $'\r' "$f" >/dev/null 2>&1; then
	echo "::error file=$f::CRLF or CR detected"
	fail=1
	fi
	done
	exit $fail

	- name: Check no trailing whitespace
	run: \|
	set -e
	fail=0
	for f in examples/*.n6; do
	if grep -nE ' +$' "$f"; then
	echo "::error file=$f::trailing whitespace"
	fail=1
	fi
	done
	exit $fail

	- name: Check entry-header well-formed
	run: \|
	set -e
	fail=0
	for f in examples/*.n6; do
	# Every @<type> line must have :: <domain> and [grade]
	bad=$(grep -nE '^@[PCLFRSXE?]' "$f" \| grep -vE ' :: \S+ \[[0-9]+(\.[0-9]+)?[!?]\]\s*$' \|\| true)
	if [ -n "$bad" ]; then
	echo "::error file=$f::malformed entry-header"
	echo "$bad"
	fail=1
	fi
	done
	exit $fail

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