chore(code-conversion): update API mapping guide

[venetrius]

related to: /issues/1041

Pull Request Template

Description

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Test-only changes (no production code changes)

Testing Checklist

Black-Box Testing Requirements

• Tests follow black-box testing approach: verify behavior through observable outputs (logs, C8 API queries, real-world skip scenarios)
• Tests DO NOT access implementation details (DbClient, IdKeyMapper, ..impl.. packages except logging constants)
• Architecture tests pass (ArchitectureTest validates these rules)

Test Coverage

• Added tests for new functionality
• Updated tests for modified functionality
• All tests pass locally

Architecture Compliance

Run architecture tests to ensure compliance:

mvn test -Dtest=ArchitectureTest

If architecture tests fail, refactor your tests to use:

• LogCapturer for log assertions
• camundaClient.new*SearchRequest() for C8 queries
• Real-World skip scenarios (e.g., migrate children without parents)

Documentation

• Updated TESTING_GUIDELINES.md if adding new test patterns
• Added Javadoc comments for public APIs
• Updated README if user-facing changes

Checklist

• Code follows project style guidelines
• Self-reviewed the code
• Added comments for complex logic
• No new compiler warnings
• Dependent changes have been merged

Related Issues

[venetrius]

This PR updates the C8 API spec and accounts for the Search jobs API.
It would also make sense to see what other APIs were added to C8.