chore: prepare v1.3.0 release

[TacoRocket]

Summary

• bump the package and schema version surfaces to 1.3.0
• add the 1.3.0 changelog entry for the credential-path verification and registry work
• refresh golden schema-version metadata and regenerate schemas for the release boundary

Verification

• python3 -m ruff check src tests scripts
• PYTHONPATH=src python3 scripts/generate_schemas.py
• PYTHONPATH=src python3 -m pytest -o cache_dir=/private/tmp/pytest-cache-dns 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 -o cache_dir=/private/tmp/pytest-cache-all
• python3 -m build
• python3 -m twine check dist/*
• fresh-venv smoke: install dist/azurefox-1.3.0-py3-none-any.whl and run azurefox help plus fixture-backed whoami