Summary

This PR renames TID254 to lazy-import-mismatch and expands it into a single rule with two complementary settings: require-lazy and ban-lazy. Both settings accept "all", list[str], or { include = ..., exclude = [...] }, and we validate that the two selectors don’t overlap.

This covers the two main use-cases users asked for:

• Require lazy imports by default, except for known side-effectful modules. Example:

  require-lazy = { include = "all", exclude = ["sitecustomize"] }

  This enforces lazy imports everywhere Ruff can rewrite them, while leaving sitecustomize eager.

• Forbid lazy imports for modules that must stay eager, or even forbid lazy imports by default with a small allowlist.

  # Require `sitecustomize` to stay eager.
  ban-lazy = ["sitecustomize"]
  
  # Ban lazy imports everywhere except `typing`.
  ban-lazy = { include = "all", exclude = ["typing"] }