feat: add acr command

[TacoRocket]

Summary

• add a narrow management-plane acr command for login server, auth, and network posture
• add fixture, schema, golden, help, and terminal UX coverage for the new slice
• park deferred follow-on depth as acr-depth

Validation

• python3 -m ruff check src tests scripts
• PYTHONPATH=src python3 scripts/generate_schemas.py
• PYTHONPATH=src python3 -m pytest tests/test_collectors.py tests/test_golden_outputs.py tests/test_contract_schemas.py tests/test_cli_smoke.py tests/test_help.py tests/test_terminal_ux.py tests/test_models.py
• PYTHONPATH=src python3 -m pytest