feat: Add type coverage support using mypy

[FallenDeity]

Completely resolves #56 and partially addresses #54

• To resolve Complete type hint coverage and add py.typed marker #56 ci required updates since particular required type hints are 3.10+

#56

• Audit existing type hints
• Add missing type hints to public APIs
• Add missing type hints to internal functions
• Add py.typed marker file to package
• Configure mypy in strict mode in pyproject.toml
• Update CI to run mypy checks
• Use modern type syntax (e.g., list[str] instead of List[str])
• Add type tests using pytest with type checking, (added mypy static type checking in ci, other option was using this https://github.com/realpython/pytest-mypy but don't think an extra dep is needed)
• Document type annotations in docstrings

#54

• Bump python version in pyproject.toml
• Update ci/cd matrix
• Reviewed all deps for 3.10+ and 3.14 compatibility, ran ci/cd workflow https://github.com/FallenDeity/redlines/actions/runs/18381510195 (all passed for new matrix)
• Code modernization done for most part (except match/case in redlines.py)
• Added a note using sys in cli.py regarding python version required

Pending or Not Done

• bump package version (needs review of existing changes before making the final commit)
• docs changes
  • I think a separate pr is in order for there where something like pre-commit is setup which runs mypy, black, isort, pytest etc automatically and contributing.md can be updated accordingly this creates a unified workflow than documenting each tool separately.
  • Also Add Python 3.14 support and drop Python 3.8/3.9 #54 says mention update versions in readme i see no such existing mention maybe we just add a badge like this?
  • No changelogs present so far either, I think that should be done along with release when bumping the package version and maybe creating a tag from maintainer side, could be a nice tool for this https://github.com/cookpete/auto-changelog

cc: @houfu

[houfu]

Looks good overall! Left a few minor suggestions but nothing blocking. Feel free to merge as-is or address them—up to you.

[houfu]

Great work on this PR! 🎉

I noticed that GitHub will automatically close both issues #54 and #56 when this PR is merged, even though the PR description says "partially resolves #54".

GitHub's parser detected the keyword "resolves" next to #54 and is treating it as an auto-close trigger, ignoring the "partially" qualifier.

Since #54 is only partially completed (with docs changes and version bump still pending), you might want to update the PR description to prevent it from auto-closing:

Current:

Completely resolves #56 and partially resolves #54

Suggested:

Resolves #56 and partially addresses #54

This way only #56 will close automatically, and #54 will remain open for the remaining work (version bump, docs, pre-commit setup, etc.).

[FallenDeity]

thx :) updated the pr desc and made the minor changes, rest of the release work can be carried over as part of #54