Add SQLite-cached check_holidays MCP tool with pre-analysis checklist

- Add check_holidays MCP tool in server.py with SQLite caching (cache-first, API-fallback)
- Add Section 6 Pre-Analysis Checklist (market status, holidays, news, analysis type) to SKILL.md
- Add holidays-data named volume to docker-compose.yml for DB persistence
- Add API_CO_ID_KEY and HOLIDAYS_DB_PATH env vars to Dockerfile and .env.example
- Remove scripts/ directory (replaced by MCP tool), slim down Dockerfile

docker-compose.yml

@@ -6,4 +6,11 @@ services:
       - "8000:8000"
     env_file:
       - .env
+    environment:
+      - HOLIDAYS_DB_PATH=/app/holidays.db
+    volumes:
+      - holidays-data:/app/holidays.db
     restart: unless-stopped
+
+volumes:
+  holidays-data: