Genesis Sprint 7: add context explanation tests and CI validation

[fadf4life]

Add automated coverage for the agentforge explain-context MVP and keep CI validation aligned with the explanation surface.

Scope:

• tests for canonical repo explanation
• tests for generated/minimal AICS project explanation
• tests for invalid context explanation
• tests for missing project path behavior
• CI updates required to run the new test surface

Acceptance criteria:

• local tests cover success and invalid-context paths for explain-context
• generated or minimal context explanation is exercised in automated tests
• CI runs the Sprint 7 test surface without secrets or network dependencies
• regressions to validate-context and init-context behavior are prevented

[fadf4life]

Shipped in 8671f1a and tagged as Genesis-0.0.7. Automated coverage now exercises context explanation for the canonical repo, scaffolded/minimal projects, incomplete context, missing paths, and editable-install smoke behavior.