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

.env.example

@@ -1,3 +1,10 @@
 # TradingView session ID for real-time data access
 # Get it from: DevTools > Application > Cookies > tradingview.com > sessionid
 TV_SESSION_ID=
+
+# API.CO.ID key for Indonesian holidays lookup
+# Get from: https://api.co.id
+API_CO_ID_KEY=
+
+# Path to SQLite database for holiday cache (default: holidays.db in server.py directory)
+HOLIDAYS_DB_PATH=