chore: implement automated linting and formatting

[yoonheeh]

Changelog

• Adds .pre-commit-config.yaml with Ruff and Clang-Format hooks.
• Adds pyproject.toml to configure Ruff (88 char line limit).
• Adds GitHub Action (.github/workflows/lint.yml) for CI style validation.
• Applies project-wide formatting and fixes all linting issues in Python and C++.
• Hardens package structure with properly defined all in init.py.

Testing

yoonhee@yoonhee:~/developments/rosbpf$ pre-commit run --all-files
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
check yaml...............................................................Passed
check for added large files..............................................Passed
ruff (legacy alias)......................................................Passed
ruff format..............................................................Passed
clang-format.............................................................Passed