Add CLAUDE.md guidance file

[iliyan-velichkov]

Summary

Adds a CLAUDE.md file to guide Claude Code (and other AI assistants) when working in this repository.

Key points captured:

• Product context (from codbex.com/products): Hades is a database-administration product — Database Explorer, SQL Console, Data Transfer, Import/Export, and Anonymization across PostgreSQL/MySQL/SAP HANA/H2/... — packaging Eclipse Dirigible components on the codbex-platform-parent foundation.
• This repo is primarily an assembly/packaging project over Eclipse Dirigible — functionality lives in the dirigible-components-* dependencies, not in this repo's source.
• Build & run commands (quick-build profile, required --add-opens JVM flags).
• Test profiles (unit-tests, integration-tests, tests) and how to run a single integration test.
• Code formatting via mvn verify -P format.
• Module layout and roles.
• Architecture notes: datasource/JPA auto-config exclusions, required Spring profiles (common, app-default), env-var datasource config, and Dirigible content-module discovery.

🤖 Generated with Claude Code