Move YAPF style setting to a project-wide .style.yapf file

[mhucka]

Scripts and workflows that run yapf currently each add the option --style=google to the invocation of yapf. To follow best practices, this PR adds a .style.yapf configuration file at the top level of the project to set the style, and removes the flag from where it was added on the command line explicitly.

The use of a config file has the following benefits:

• It lets tools like IDEs discover the setting automatically.
• It reduces the chances that developers will forget to add the flag when they run yapf directly on the command line for quick checks, or write new scripts that use yapf.
• It communicates intentions more clearly to new contributors.

Removing the flag from the scripts is not strictly necessary (everything will work the same if there is both a config file and the flag is passed to yapf). However, if a config file is used, it's better for maintainability and consistency to also remove the flag from individual invocations.

[gemini-code-assist]

Code Review

This pull request adds a .style.yapf configuration file to set the Python formatting style to Google. The review feedback suggests updating existing formatting scripts to remove hardcoded style flags, ensuring this new file serves as the single source of truth, and recommends adding a .clang-format file for C++ consistency.

[mhucka]

/gemini review

[gemini-code-assist]

Code Review

This pull request centralizes the YAPF configuration by introducing a .style.yapf file and removing redundant style flags from the formatting scripts. Feedback suggests invoking yapf via python3 -m in format_check.sh for better environment consistency and providing the filename parameter to the YAPF API in format_ipynb.py to ensure the new configuration file is properly detected.

[gemini-code-assist]

For consistency with scripts/format_all.sh and to ensure the correct environment is used, it is recommended to invoke yapf using python3 -m yapf. This avoids potential issues where the yapf executable in the PATH might be associated with a different Python interpreter or version than the one intended for the project.

Suggested change

	results=$(yapf --diff "${changed_file}" ${changed_line_ranges})
	results=$(python3 -m yapf --diff "${changed_file}" ${changed_line_ranges})

[gemini-code-assist]

When using the yapf API without an explicit style_config, it is best practice to provide the filename argument. This allows yapf to search for the nearest configuration file (like the newly added .style.yapf) relative to the file being formatted, making the script more robust if run from different directories or if different parts of the project eventually require different styles.

Suggested change

	fmt_lines = yapf.yapf_api.FormatCode(''.join(lines))[0]
	fmt_lines = yapf.yapf_api.FormatCode(''.join(lines), filename=fname)[0]