Initial commit: CodiMD Docker deployment with security hardening

- Add docker-compose.yml with PostgreSQL and CodiMD services
- Add .env.example for environment configuration template
- Add .gitignore to exclude sensitive data and persisted volumes
- Add CLAUDE.md documentation for deployment guidance
- Security hardening: read-only containers, health checks, network isolation

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,8 @@
+# Environment variables with sensitive data
+.env
+
+# PostgreSQL data
+pgdata/
+
+# CodiMD uploaded files
+upload-data/