fix(ruff): preserve non-check subcommands

[fengjikui]

Summary

Fixes #2669.

rtk ruff previously treated every first positional argument except format and version as a check target. That meant real Ruff subcommands such as rule, config, and linter were rewritten as ruff check --output-format=json ..., which makes those subcommands fail.

This changes the routing logic to use a known Ruff subcommand allowlist. Paths such as src and explicit check still route through the JSON check path, while non-check subcommands pass through unchanged.

Validation

• cargo test test_ruff_ -- --nocapture
• cargo fmt --check && cargo test ruff_cmd -- --nocapture