chore: use uv as the dependencies installer

[FrenchGithubUser]

but keep using hatch for everything else since we get most of uv's benefits on the dependencies installation step and its other benefits are not worth enough for the change

[cursor]

PR Summary

Low Risk
Dev-tooling-only change in pyproject.toml with no runtime or application code impact; risk is limited to local/CI Hatch env setup needing uv available.

Overview
Configures Hatch’s default dev environment to install dependencies with uv instead of the default pip backend, by setting installer = "uv" under [tool.hatch.envs.default] in pyproject.toml.

Hatch remains the workflow for envs, scripts, tests, and static analysis; only the install step for that default env changes, aimed at faster dependency resolution/installation without migrating the rest of the tooling to uv.

^{Reviewed by Cursor Bugbot for commit d4ceda4. Bugbot is set up for automated code reviews on this repo. Configure here.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.47%. Comparing base (065f7fb) to head (d4ceda4).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #50   +/-   ##
=======================================
  Coverage   93.47%   93.47%           
=======================================
  Files          10       10           
  Lines         904      904           
  Branches      135      135           
=======================================
  Hits          845      845           
  Misses         34       34           
  Partials       25       25           

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