Add pre-push checksum update

scripts/update_checksum.py

@@ -0,0 +1,26 @@
+import sys
+from pathlib import Path
+
+# Ensure src directory is in sys.path for imports
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+SRC_DIR = PROJECT_ROOT / "src"
+if str(SRC_DIR) not in sys.path:
+    sys.path.insert(0, str(SRC_DIR))
+
+from utils.checksum import calculate_checksum
+from constants import SCRIPT_CHECKSUM_FILE
+
+
+def main() -> None:
+    """Calculate checksum for the main script and write it to SCRIPT_CHECKSUM_FILE."""
+    script_path = SRC_DIR / "password_manager" / "manager.py"
+    checksum = calculate_checksum(str(script_path))
+    if checksum is None:
+        raise SystemExit(f"Failed to calculate checksum for {script_path}")
+
+    SCRIPT_CHECKSUM_FILE.write_text(checksum)
+    print(f"Updated checksum written to {SCRIPT_CHECKSUM_FILE}")
+
+
+if __name__ == "__main__":
+    main()