feat: Set review_code include/exclude paths in config file

[sttlr]

This PR adds the ability to set review_code_include_paths and review_code_exclude_paths in config file.

Options are used when review_code is invoked.

It allows to run focused reviews and do it much faster:

• metis woudn't waste time on reviewing definition files (dtos, types...) or tests
• metis woudn't report "issues" with definition files (dtos, types...) or tests - which probably in 100% of the cases I don't care about

Why not use metisignore

I treat metisignore file as a global ignore file - essentially .gitignore clone. It lists files that model should never see or interact with (e.g. .venv, node_modules...)

But it lacks the ability to set files and folders that I'd like to include or exclude from code review process:

• changing --codebase-path is not an option because it changes the base directory and messes with metisignore file (it will not be loaded)
• defining paths to exclude in metisignore file is a bad design choice because I only want to exclude paths from review_code (to not run review_file on them) but not completely. Because those files might be useful in Relevant Context (gathered via embeddings or tools).

Example Usage

metis_engine:
  review_code_include_paths:
    - 'backend/'
  review_code_exclude_paths:
    - 'dto/'
    - '*.d.ts'
    - '*.spec.ts'
    - '*.fixture.ts'
    - '*.dto.ts'
    - '*.const.ts'
    - '*.interface.ts'
    - '*.model.ts'
    - '*.type.ts'
    - '*.request.ts'
    - '*.response.ts'
    - '*.response.api.ts'
    - '*.params.ts'
    - '*.schema.ts'
    - '*.mapper.ts'
    - '*.store.ts'
    - 'e2e_ssr/'
    - 'e2e/'
    - '*.e2e-spec.ts'
    - 'backend/test'
    - 'schema.ts'

It configures to run review_code only in the backend/ folder and defines files and folders to exclude from individual review.

Excluded files are not important and shoudn't be reviewed individually - BUT they could and should be used for Relevant Context. That's why the need for these options.

Testing

Passes pre-commit and tests.

Run review_code on actual project to test that it works accordingly.

[mpekatsoula]

Can you also document this and maybe add an example in the examples folder?
Other than that your code makes sense, nice addition thanks @sttlr