Standardize database naming and fix environment configuration

- Renamed database from 'decision_tree' to 'apoklisis' for consistency
- Updated docker-compose.yml: container renamed to 'apoklisis_postgres'
- Updated .env file with correct database URL
- Verified backend authentication flow working correctly
- Added postgres MCP server to Claude Code configuration

PROGRESS.md

@@ -17,6 +17,11 @@ Building a troubleshooting decision tree web application for MSP engineers. The
 
 ---
 
+# Apoklisis Development Progress
+
+> 📚 **Reference**: See [CLAUDE-SETUP.md](./CLAUDE-SETUP.md) for available
+> development tools and usage guidelines
+
 ## Completed Work
 
 ### Phase 1a: Backend API (COMPLETE)