chore: migrate to uv+ruff

[weiiwang01]

Automatic pull request to migrate the Python project to use uv, tox-uv, and ruff for building, testing and linting.

The changes include:

• Merge requirements.txt into pyproject.toml
• Migrate tox.ini to tox.toml
• Replace tox with tox-uv
• Use ruff for linting and formatting, replacing flake8, pylint, black, and isort
• Fix some linting issue discovered by ruff

[weiiwang01]

@copilot Please fix any unit test or linting issues caused by the migration to uv and ruff in this pull request.

• For unit test failures, update the tests while preserving the original intention of each test as much as possible.
• For linting failures:
  • If the lint rule is reasonable in the context, update the source code to satisfy the lint check.
  • If the lint rule is not reasonable in this context, disable the specific lint check with an inline ignore comment. If the reason is not obvious, add a brief comment explaining why the lint check is being disabled.

You can run the relevant checks by invoking the unit,lint,static environment of tox-uv.

[weiiwang01]

@copilot Please fix any unit test or linting issues caused by the migration to uv and ruff in this pull request.

• For unit test failures, update the tests while preserving the original intention of each test as much as possible.
• For linting failures:
  • If the lint rule is reasonable in the context, update the source code to satisfy the lint check.
  • If the lint rule is not reasonable in this context, disable the specific lint check with an inline ignore comment. If the reason is not obvious, add a brief comment explaining why the lint check is being disabled.

You can run the relevant checks by invoking the unit,lint,static environment of tox-uv.

[Copilot]

@weiiwang01 I've opened a new pull request, #71, to work on those changes. Once the pull request is ready, I'll request review from you.