fix(airflow): remove DAG volume mounts, use image-baked DAGs

The named volume was shadowing the DAGs built into the pipeline image
with an empty directory. DAGs now served directly from the image and
update on each CI build.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -117,7 +117,7 @@ services:
       TYPESENSE_URL: http://typesense:8108
       TYPESENSE_API_KEY: ${TYPESENSE_API_KEY:-changeme}
     volumes:
-      - ./pipeline/dags:/opt/pipeline/dags:ro
+
     depends_on:
       db:
         condition: service_healthy
@@ -137,7 +137,7 @@ services:
     command: airflow scheduler
     environment: *airflow-env
     volumes:
-      - ./pipeline/dags:/opt/pipeline/dags:ro
+
     depends_on:
       db:
         condition: service_healthy