chore: add Ruff pre-commit checks

[gabrielfruet]

What has changed and why?

Added the existing Ruff checks to pre-commit so contributors can run the same Python
checks locally with one command.

Updated make format-check to use pre-commit and refreshed CONTRIBUTING.md to point
to the new workflow.

How has it been tested?

• pre-commit run --all-files
• make format-check
• Manual hook proof with a temporary bad Python file:
  • ruff-format-check failed on bad formatting, passed after fixing
  • ruff-check failed on lint errors, passed after fixing

Did you update CHANGELOG.md?

• Yes
• Not needed (internal change)

Did you update the documentation?

• Yes
• Not needed (internal change without effects for user)

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Include notebooks in Ruff hook file filters

The new local Ruff hooks are restricted to types_or: [python], which means pre-commit will not pass .ipynb files to either ruff format --check or ruff check. This is a regression from the previous ruff ... . commands in format-check, which did include notebooks (Ruff currently discovers examples/notebooks/*.ipynb by default). As a result, notebook code can now bypass lint/format checks in both pre-commit run --all-files and make format-check.

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[Copilot]

Pull request overview

This PR integrates the repository’s existing Ruff formatting/linting checks into pre-commit, updates make format-check to delegate to pre-commit, and refreshes contributor documentation to reflect the new workflow.

Changes:

• Updated make format-check to run pre-commit run --all-files instead of invoking Ruff directly.
• Added local pre-commit hooks for ruff format --check and ruff check.
• Updated CONTRIBUTING.md to recommend running pre-commit-based checks before committing.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
Makefile	Switches format-check to run pre-commit hooks (instead of direct Ruff commands).
CONTRIBUTING.md	Updates the recommended local workflow to include pre-commit.
.pre-commit-config.yaml	Adds Ruff check hooks to pre-commit (local/system hooks).

Comments suppressed due to low confidence (2)

.pre-commit-config.yaml:30

• language: system for this Ruff hook makes the pre-commit run depend on whatever ruff is available on the user's PATH at commit time (e.g., it can fail when the virtualenv isn’t activated, and it doesn’t pin a Ruff version). Consider using the official astral-sh/ruff-pre-commit repo (pinned rev) or a non-system hook setup so pre-commit manages the Ruff environment consistently.

      - id: ruff-check
        name: ruff check
        entry: ruff check
        language: system
        types_or: [python]

.pre-commit-config.yaml:31

• With types_or: [python], this hook will not run on Jupyter notebooks (.ipynb). Previously ruff format --check . / ruff check . (in make format-check) would also cover notebooks under examples/notebooks, so this is a behavior change and may miss issues there. Consider expanding the hook to include .ipynb files (e.g., via an appropriate types/files matcher).

        entry: ruff check
        language: system
        types_or: [python]
        description: "Run Ruff lint checks."