fix(ci): use Benchmark.js instead of Vitest Bench for CI/CD

- Switch from Vitest Bench to Benchmark.js for GitHub Actions
- Install and build benchmarks in CI workflow
- Extract JSON results from Benchmark.js output
- Add PR comments with benchmark results
- Upload both JSON and text results as artifacts
- Only push to gh-pages on main branch (not PRs)

Fixes:
- ENOENT error for bench-results.json
- Vitest Bench doesn't generate JSON output automatically
- Use industry-standard Benchmark.js for consistent results

Benefits:
- More accurate performance measurements
- Consistent with README documentation
- Better integration with github-action-benchmark
- Automatic PR comments with results

Author: Isqanderm

.github/workflows/benchmark.yml

@@ -37,13 +37,32 @@ jobs:
       - name: Build project
         run: npm run build
 
-      - name: Run benchmarks
-        run: npm run bench
+      - name: Install benchmark dependencies
+        run: cd benchmarks && npm ci
+
+      - name: Build benchmarks
+        run: cd benchmarks && npm run build
+
+      - name: Run simple benchmark
+        run: cd benchmarks && node build/benchmarks/simple/Mapper.performance-benchmark.js > ../benchmark-simple.txt
+
+      - name: Run complex benchmark
+        run: cd benchmarks && node build/benchmarks/complex/Mapper.performance-benchmark.complex.js > ../benchmark-complex.txt
+
+      - name: Parse benchmark results
+        id: parse-results
+        run: |
+          # Extract JSON from benchmark output (last 13 lines contain the JSON array)
+          cd benchmarks
+          node build/benchmarks/simple/Mapper.performance-benchmark.js 2>&1 | tail -n 13 > ../bench-results.json
+          echo "Benchmark results:"
+          cat ../bench-results.json
 
       - name: Store benchmark result
         uses: benchmark-action/github-action-benchmark@v1
+        if: github.event_name != 'pull_request'
         with:
-          name: Vitest Benchmark
+          name: Benchmark.js Performance
           tool: 'benchmarkjs'
           output-file-path: bench-results.json
           github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -60,6 +79,39 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: benchmark-results
-          path: bench-results.json
+          path: |
+            bench-results.json
+            benchmark-simple.txt
+            benchmark-complex.txt
           retention-days: 30
 
+      - name: Comment PR with results
+        if: github.event_name == 'pull_request'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            const simpleResults = fs.readFileSync('benchmark-simple.txt', 'utf8');
+            const complexResults = fs.readFileSync('benchmark-complex.txt', 'utf8');
+
+            const body = `## 📊 Benchmark Results
+
+            ### Simple Mapping
+            \`\`\`
+            ${simpleResults}
+            \`\`\`
+
+            ### Complex Transformations
+            \`\`\`
+            ${complexResults}
+            \`\`\`
+
+            *Benchmarked with Benchmark.js on Node.js 20*`;
+
+            github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: body
+            });
+