Implemented a standardized folder structure for domain documentation to improve clarity and maintainability. Migrated existing files to the new structure, updated links in related documentation, and added README files for navigation and guidance.
* chore(MP-21): snapshot pre-refactor state (Epic 1) * chore(MP-22): scaffold new repo structure, relocate Docker Compose, move frontend/backend modules, update Makefile; add docs mapping and env template * MP-22 Epic 2: Erfolgreich umgesetzt und verifiziert * MP-23 Epic 3: Gradle/Build Governance zentralisieren
