feat: slhx requirements, project structure, and core primitives

.githooks/commit-msg

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -euo pipefail
+msg_file="$1"
+# Require scope if REQs exist
+if [ -f REQUIREMENTS.md ]; then
+  if ! grep -qE '^[a-z]+(\(.+\))?:' "$msg_file"; then
+    echo "error: commit requires scope — e.g. feat(parser): ..."
+    exit 1
+  fi
+fi