Enhance code-migration-detector to allow code analysis.

[ManuelDittmar]

Is your feature request related to a problem? Please describe.

Migration effort can be seen based on the diagram converter, however currently there is no tooling available to analyze the code base.

Describe the solution you'd like

Prevent New Camunda 7 Implementations

User Story

As a system architect,
I want to ensure that no new implementations are added using Camunda 7 specific APIs and patterns,
so that we avoid complicating the upcoming migration to Camunda 8.

Acceptance criteria

• Given that that a developer is adding or modifying a process solution,
• when the changes are submitted,
• then the CI/CD pipeline should automatically check for and reject any use of deprecated Camunda 7 APIs

Tasks

• Develop ArchUnit rules to detect deprecated Camunda 7 APIs
• Allow ignoring old violations

On-Demand Reporting of Camunda 7 Migration Challenges

User Story

As a system architect,
I want to have the ability to trigger an analysis that generates a detailed report of Camunda 7 architectural violations
so that I can proactively assess and plan the migration to Camunda 8

Acceptance criteria

• Given that I trigger the analysis,
• when the analysis runs on the current codebase,
• then the tool should evaluate the current code base for Camunda 7-specific architectural violations, generate a detailed report that includes each violation, explains the implications for migration to Camunda 8, and provides suggestions that conform to Camunda 8 best practices, potentially linking to documentation or examples for further guidance.

Tasks

• Enhance ArchUnit reporting to include detailed violation analysis and migration guidance
• Document how to generate a report on-demand.

Missing Tests

• Engine Plugin

Describe alternatives you've considered

• For now I would like to build the solution on top of the existing ArchUnit Implementation: https://github.com/camunda-community-hub/camunda-7-to-8-migration/tree/main/code-migration-detector

Additional context

Implementation will be discussed with @jonathanlukas

[ingorichtsmeier]

I've improved the README with a working MigrationPreparationTest.