chore: bootstrap project scaffold

tests/test_smoke.py

@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+from pathlib import Path
+
+
+def test_main_runs_headless() -> None:
+    repo_root = Path(__file__).resolve().parents[1]
+    env = os.environ.copy()
+    env["AI_SIDEBAR_HEADLESS"] = "1"
+
+    result = subprocess.run(
+        [sys.executable, "main.py"],
+        cwd=repo_root,
+        env=env,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        text=True,
+        check=False,
+    )
+
+    assert result.returncode == 0
+    assert "Headless mode enabled" in result.stdout