fix: address concurrency issues and add stress tests

.github/workflows/stress.yml

@@ -0,0 +1,34 @@
+name: Stress tests
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  jcstress:
+    name: JCStress
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: corretto
+          java-version: 23
+
+      - name: Make Gradle executable
+        run: chmod +x ./gradlew
+
+      - name: Run JCStress tests
+        run: ./gradlew :futur-jcstress:jcstress
+
+      - name: Upload JCStress report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: jcstress-report
+          path: futur-jcstress/build/reports/jcstress/