Harden Python codegen formatting

[hardbyte]

Summary

• keep Python codegen's missing-Ruff fallback to basic formatting
• fail Python codegen when ruff format is found but exits non-zero
• make --format=false a working escape hatch while preserving bare -f/--format
• render multi-field Rust tuple structs as Python RootModel[tuple[...]] instead of invalid numeric fields
• document Ruff as a generated-code formatter dependency for consistent output and pin the Rust CI job to the same Ruff version as the Python smoke test

Validation

• cargo fmt --check
• cargo test -p reflectapi-cli
• cargo test -p reflectapi --lib
• cargo run -p reflectapi-cli --quiet -- codegen -s reflectapi-demo/reflectapi.json -o /tmp/reflectapi-no-ruff-check-client -l python --python-package-name api_client --python-sync -f with Ruff absent from PATH
• cargo test -p reflectapi-demo tests::basic::test_reflectapi_struct_tuple -- --nocapture with Ruff on PATH
• cargo test -p reflectapi-demo test_python_split_modules -- --nocapture with Ruff on PATH
• cargo test -p reflectapi-demo --test codegen_coverage -- --nocapture with Ruff on PATH
• cargo test -p reflectapi-demo tests::write_python_client -- --nocapture with Ruff on PATH

[github-actions]

📖 Documentation Preview: https://reflectapi-docs-preview-pr-160.partly.workers.dev

Updated automatically from commit 635290c