ci: add commit linter

.commitlintrc.js

@@ -0,0 +1,3 @@
+export default {
+  extends: ["@commitlint/config-conventional"],
+};

.github/workflows/lint.yml

@@ -1,6 +1,7 @@
 name: Lint
 
 on:
+  push:
   pull_request:
   workflow_call:
 
@@ -13,9 +14,35 @@ jobs:
       - uses: actions/setup-go@v5
         with:
           go-version: "1.22"
-          cache: false
+          cache: false # Disable cache since golangci-lint does its own caching
 
       - name: Lint source code
         uses: golangci/golangci-lint-action@v4
         with:
           version: latest
+
+  commitlint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: lts/*
+
+      - name: Install commitlint
+        run: |
+          npm install conventional-changelog-conventionalcommits
+          npm install commitlint@latest
+
+      - name: Validate current commit (last commit) with commitlint
+        if: github.event_name == 'push'
+        run: npx commitlint --last --verbose
+
+      - name: Validate PR commits with commitlint
+        if: github.event_name == 'pull_request'
+        run: >-
+          npx commitlint
+          --from ${{ github.event.pull_request.head.sha }}~${{ github.event.pull_request.commits }}
+          --to ${{ github.event.pull_request.head.sha }}
+          --verbose