Restore hate_crack package and add E2E install tests

tests/test_docker_script_install.py

@@ -0,0 +1,48 @@
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.skipif(
+    os.environ.get("HATE_CRACK_RUN_DOCKER_TESTS") != "1",
+    reason="Set HATE_CRACK_RUN_DOCKER_TESTS=1 to run Docker-based tests.",
+)
+def test_docker_script_install_and_run():
+    if shutil.which("docker") is None:
+        pytest.skip("docker not available")
+
+    repo_root = Path(__file__).resolve().parents[1]
+    image_tag = "hate-crack-e2e"
+
+    try:
+        build = subprocess.run(
+            ["docker", "build", "-f", "Dockerfile.test", "-t", image_tag, str(repo_root)],
+            capture_output=True,
+            text=True,
+            timeout=600,
+        )
+    except subprocess.TimeoutExpired as exc:
+        pytest.fail(f"Docker build timed out after {exc.timeout}s")
+
+    assert build.returncode == 0, (
+        "Docker build failed. "
+        f"stdout={build.stdout} stderr={build.stderr}"
+    )
+
+    try:
+        run = subprocess.run(
+            ["docker", "run", "--rm", image_tag],
+            capture_output=True,
+            text=True,
+            timeout=120,
+        )
+    except subprocess.TimeoutExpired as exc:
+        pytest.fail(f"Docker run timed out after {exc.timeout}s")
+
+    assert run.returncode == 0, (
+        "Docker script install/run failed. "
+        f"stdout={run.stdout} stderr={run.stderr}"
+    )