chore: import upstream snapshot with attribution

commitlint.config.js

@@ -0,0 +1,17 @@
+module.exports = {
+  extends: ["@commitlint/config-conventional"],
+  // Skip standard git merge commits (e.g. "Merge pull request #N",
+  // "Merge branch '...'"). The push-path workflow additionally guards
+  // `--last` with a parent-count check so GitHub "Create a merge commit"
+  // style merges (which take their message from the PR body and can
+  // therefore contain markdown lists that parse as empty subjects) are
+  // skipped before commitlint even runs.
+  ignores: [(message) => /^Merge /.test(message)],
+  rules: {
+    "subject-case": [0],
+    // GitHub merge commits append " (#NNNN)" which eats 8+ chars.
+    // With scoped conventional prefixes like "fix(runtime): ...",
+    // 100 chars is too tight. 120 gives enough room.
+    "header-max-length": [2, "always", 120],
+  },
+};