added asset to read agency_list.csv and add it to table in gtfs.duckdb

user_code/gtfs/assets.py

@@ -0,0 +1,18 @@
+import pandas as pd
+from dagster import asset
+from dagster_duckdb import DuckDBResource
+
+
+@asset
+def agency_list(duckdb: DuckDBResource) -> None:
+    """Load agency list from CSV into DuckDB."""
+
+    # Read the CSV (path is relative to container working directory)
+    df = pd.read_csv('data/gtfs/agency_list.csv')
+
+    # Write to DuckDB
+    with duckdb.get_connection() as conn:
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS agency_list AS
+            SELECT * FROM df
+        """)