Maintenance- & dbt-Cleanup-Release

🧩 v0.2.2 — Dependency cleanup and preparation for 0.3.x

This maintenance release removes all remaining dbt references and artifacts,
clarifying elevata’s direction as a fully independent metadata platform.

Changes:

• removed dbt_project/ folder and DBT_* environment variables
• updated README, NOTICE, and strategy docs
• unified AGPLv3 license references
• minor documentation and wording cleanups

Next milestone: 0.3.x – native target model generation, surrogate keys, and full independence.

Full Changelog: v0.2.1...v0.2.2