chore: add drf-lint pre-commit hook with baseline

[blarghmatey]

What are the relevant tickets?

N/A

Description (What does it do?)

Adds the drf-serializer-orm-check pre-commit hook from mitodl/ol-django which uses mitol-drf-lint to detect Django ORM queries inside DRF serializer methods — a common source of N+1 query bugs.

Also generates an initial drf_lint_baseline.json recording all pre-existing violations so the hook only flags new issues going forward. Existing violations can be addressed incrementally.

mitol-drf-lint is added as a dev dependency to support running the tool locally outside of pre-commit.

How can this be tested?

1. Install pre-commit hooks: pre-commit install
2. Modify or create a serializers.py file that calls ORM methods (e.g. .filter(), .get()) inside a serializer method
3. Attempt to commit — the hook should flag the new violation
4. Alternatively, run directly: uv run drf-lint <path/to/serializers.py>

Additional Context

The baseline was generated with:

uv run drf-lint --generate-baseline --baseline drf_lint_baseline.json $(find . -name "serializers.py" ! -path "*/migrations/*")

[gemini-code-assist]

Code Review

This pull request establishes a pre-commit workflow by adding a configuration file with various linting hooks and integrating the mitol-drf-lint tool. The changes also include a baseline file for serializer violations and updated project dependencies. Review feedback identifies several necessary adjustments to the pre-commit hooks, including adding the baseline argument to the DRF linter, updating the ruff version, and switching the eslint and scss-lint hooks to use the system language for proper execution.

[gemini-code-assist]

The drf-serializer-orm-check hook is missing the --baseline argument. Based on the PR description and the inclusion of drf_lint_baseline.json, this argument is required for the linter to ignore existing violations. Without it, the hook will report all pre-existing issues on every commit, defeating the purpose of the baseline.

      - id: drf-serializer-orm-check
        args: ["--baseline", "drf_lint_baseline.json"]

[gemini-code-assist]

The version of ruff specified (v0.0.287) is significantly outdated. It is recommended to update to a more recent version (e.g., v0.9.7) to benefit from numerous bug fixes, new linting rules, and performance improvements.

    rev: "v0.9.7"

[gemini-code-assist]

The local eslint hook uses language: node with npx but does not define additional_dependencies. This configuration will likely fail in the pre-commit managed environment. If the intention is to use the tools installed in the project's local node_modules, language: system should be used instead.

        language: system

[gemini-code-assist]

For the scss-lint hook, the $@ placeholder is unnecessary as pre-commit automatically appends the file list to the command. Additionally, similar to the eslint hook, language: system should be used if you intend to rely on the local node_modules via npx.

        entry: npx stylelint --allow-empty-input --fix
        language: system