Fix MATLAB-Python .ndi folder compatibility

Rename database file from `ndi.db` to `did-sqlite.sqlite` and binary
storage directory from `binary/` to `files/` to match NDI-MATLAB's
.ndi folder layout, so datasets downloaded by either language can be
opened by the other.

https://claude.ai/code/session_0113MRjbNRY1VZQbn84uav4w

Author: claude

src/ndi/database.py

@@ -216,17 +216,18 @@ def __init__(self, session_path: str | Path, db_name: str = ".ndi", **backend_kw
         db_dir.mkdir(parents=True, exist_ok=True)
 
         # Initialize SQLite driver (wraps DID-python's SQLiteDB)
-        db_path = db_dir / "ndi.db"
+        db_path = db_dir / "did-sqlite.sqlite"
         self._driver = SQLiteDriver(db_path, **backend_kwargs)
 
-        # Binary directory for file attachments
-        self._binary_dir = self.session_path / db_name / "binary"
+        # Binary/files directory for file attachments
+        # Named "files" for compatibility with NDI-MATLAB
+        self._binary_dir = self.session_path / db_name / "files"
         self._binary_dir.mkdir(parents=True, exist_ok=True)
 
     @property
     def database_path(self) -> Path:
         """Path to the SQLite database file."""
-        return self.session_path / self._db_name / "ndi.db"
+        return self.session_path / self._db_name / "did-sqlite.sqlite"
 
     @property
     def binary_path(self) -> Path:

tests/test_database.py

@@ -64,7 +64,7 @@ def test_create_database(self, temp_session):
         db = Database(temp_session)
         assert db.session_path == temp_session
         assert (temp_session / ".ndi").exists()
-        assert (temp_session / ".ndi" / "ndi.db").exists()
+        assert (temp_session / ".ndi" / "did-sqlite.sqlite").exists()
 
     def test_create_with_custom_db_name(self, temp_session):
         """Test creating database with custom name."""
@@ -395,7 +395,7 @@ def test_database_path(self, temp_session):
         """Test database_path property points to SQLite file."""
         db = Database(temp_session)
         assert db.database_path.exists()
-        assert str(db.database_path).endswith("ndi.db")
+        assert str(db.database_path).endswith("did-sqlite.sqlite")
 
     def test_binary_path(self, temp_session):
         """Test binary_path property."""