fix: add scrapy_code named volume for scrapy and scrapyrt services

Both scrapy and scrapyrt services now use the shared scrapy_code named
volume instead of bind mounts. Code directory will be added later.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

scrapy/compose.yaml

@@ -30,7 +30,7 @@ services:
     container_name: ${SCRAPY_COMPOSE_PROJECT_NAME}_scrapy
     command: bash
     volumes:
-      - ./code:/code
+      - scrapy_code:/code
     working_dir: /code
     restart: unless-stopped
     environment:
@@ -56,6 +56,8 @@ services:
 volumes:
   scrapyd_data:
     name: ${SCRAPY_COMPOSE_PROJECT_NAME}_scrapyd_data
+  scrapy_code:
+    name: ${SCRAPY_COMPOSE_PROJECT_NAME}_scrapy_code
 
 networks:
   compose_network: