Fix/version check workflow

.github/workflows/check-version-bump.yml

@@ -1,11 +1,10 @@
-# Ensures package.json and CHANGELOG.md are bumped compared to the latest tag when relevant files change.
+# Catches when developers forget to add a version bump for their changes.
+# Code changes (lib/, webpack/, dist/) require package.json + CHANGELOG.md.
+# Skips for: test-only, docs, .github (workflows/config).
 name: Check Version Bump
 
 on:
   pull_request:
-    paths:
-      - 'package.json'
-      - 'CHANGELOG.md'
 
 jobs:
   version-bump:
@@ -17,12 +16,44 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Detect changed files and version bump
+        id: detect
+        run: |
+          if git rev-parse HEAD^2 >/dev/null 2>&1; then
+            FILES=$(git diff --name-only HEAD^1 HEAD^2)
+          else
+            FILES=$(git diff --name-only HEAD~1 HEAD)
+          fi
+          VERSION_FILES_CHANGED=false
+          echo "$FILES" | grep -qx 'package.json' && VERSION_FILES_CHANGED=true
+          echo "$FILES" | grep -qx 'CHANGELOG.md' && VERSION_FILES_CHANGED=true
+          echo "version_files_changed=$VERSION_FILES_CHANGED" >> $GITHUB_OUTPUT
+          # Only lib/, webpack/, dist/, package.json count as release-affecting; .github/ and test/ do not
+          CODE_CHANGED=false
+          echo "$FILES" | grep -qE '^lib/|^webpack/|^dist/' && CODE_CHANGED=true
+          echo "$FILES" | grep -qx 'package.json' && CODE_CHANGED=true
+          echo "code_changed=$CODE_CHANGED" >> $GITHUB_OUTPUT
+
+      - name: Skip when only test/docs/.github changed
+        if: steps.detect.outputs.code_changed != 'true'
+        run: |
+          echo "No release-affecting files changed (e.g. only test/docs/.github). Skipping version-bump check."
+          exit 0
+
+      - name: Fail when version bump was missed
+        if: steps.detect.outputs.code_changed == 'true' && steps.detect.outputs.version_files_changed != 'true'
+        run: |
+          echo "::error::This PR has code changes but no version bump. Please bump the version in package.json and add an entry in CHANGELOG.md."
+          exit 1
+
       - name: Setup Node
+        if: steps.detect.outputs.code_changed == 'true' && steps.detect.outputs.version_files_changed == 'true'
         uses: actions/setup-node@v4
         with:
           node-version: '22.x'
 
       - name: Check version bump
+        if: steps.detect.outputs.code_changed == 'true' && steps.detect.outputs.version_files_changed == 'true'
         run: |
           set -e
           PKG_VERSION=$(node -p "require('./package.json').version.replace(/^v/, '')")