Scope task takeover work by repository

[eshulman2]

Summary

• tell task-takeover implementers exactly which repository is mounted and defer all other repository plan sections
• pass the same repository scope into the in-container auto-review loop
• scope the later qualitative review so it does not reject work for missing changes assigned to another repository
• add regression assertions across implementation and both review layers

Context

Multi-repository plans are executed in single-repository workspaces. AISOS-2385 passed the full API-and-installer plan into an API-only container, allowing implementers and reviewers to treat absent installer files as incomplete API work.

Testing

• Ruff passed for all six changed files
• 59 focused tests passed