feat: add database module with schema initialization

Made-with: Cursor

tests/test_db.py

@@ -0,0 +1,30 @@
+import sqlite3
+
+import pytest
+
+from ntr_fetcher.db import Database
+
+
+@pytest.fixture
+def db(tmp_path):
+    db_path = str(tmp_path / "test.db")
+    database = Database(db_path)
+    database.initialize()
+    return database
+
+
+def test_tables_created(db):
+    conn = sqlite3.connect(db.path)
+    cursor = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' ORDER BY name"
+    )
+    tables = [row[0] for row in cursor.fetchall()]
+    conn.close()
+    assert "tracks" in tables
+    assert "shows" in tables
+    assert "show_tracks" in tables
+
+
+def test_initialize_idempotent(db):
+    """Calling initialize twice doesn't raise."""
+    db.initialize()