chore: import upstream snapshot with attribution

tests/test_root_start_scripts.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+_ROOT = Path(__file__).parent.parent
+
+
+def test_start_sh_exists() -> None:
+    assert (_ROOT / "start.sh").exists(), "start.sh must exist at repo root"
+
+
+def test_start_ps1_exists() -> None:
+    assert (_ROOT / "start.ps1").exists(), "start.ps1 must exist at repo root"
+
+
+def test_start_sh_is_executable() -> None:
+    if sys.platform.startswith("win"):
+        return  # git mode bits not enforced on Windows
+    mode = (_ROOT / "start.sh").stat().st_mode
+    assert mode & 0o111 != 0, "start.sh must have executable bit set"