chore: modernize analytics package tooling (uv, ruff, pyproject)

[NoopDog]

Follow-up from #4927 / #4933, where a star-import re-export leak had the potential to break a consumer in a way no tooling caught.

Problem

The analytics package has no Python linting and legacy packaging:

• No ruff/flake8/pylint config anywhere in the repo, and CI never runs against the Python code (deploy-analytics.yml only uploads the static gh-pages output).
• Packaging is a bare setuptools setup.py with no pyproject.toml; dependencies are managed with pip + venv + a hand-pinned analytics/requirements.txt.

The star-import bug fixed in #4933 (report_elements.py re-exporting entities/_report_utils names, with fetch.py depending on the leak) is exactly what ruff's F403/F405 rules flag out of the box — it would have been caught at authoring time instead of costing an issue and a PR.

Suggested fix

1. Add a pyproject.toml to analytics/analytics_package and move the setup.py metadata into it (setuptools setup.py-only packaging is deprecated, and ruff config wants a pyproject.toml anyway).
2. Add ruff with a minimal config — defaults plus the F rules (F403/F405 are the ones that would have caught chore: make analytics package public exports explicit (remove star-import leak) #4927); run ruff check and ruff format --check clean on the existing code, fixing or explicitly ignoring what surfaces.
3. Add a CI step to run-checks.yml (or a small dedicated workflow) that runs ruff on changes under analytics/** — a linter nobody runs is decoration.
4. Migrate dependency management to uv: uv.lock replacing the hand-pinned analytics/requirements.txt, and update analytics/readme.md setup instructions accordingly.

Verification

• ruff check passes locally and in CI; a deliberately introduced from x import * usage fails the check.
• Fresh-venv generate_static_site.py run including historic_data_path, per the chore: retire legacy analytics formats — tracking #4913 verification convention, to confirm packaging changes didn't break the editable install.