Update Vitest Setup

[clarasb]

This PR fixes the Frontend CI by removing canvas from the test setup. vitest.setup.ts now uses vitest-canvas-mock instead.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.91%. Comparing base (9b3e945) to head (1ff0e27).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #143   +/-   ##
=======================================
  Coverage   92.91%   92.91%           
=======================================
  Files          90       90           
  Lines        1553     1553           
  Branches      236      236           
=======================================
  Hits         1443     1443           
  Misses         92       92           
  Partials       18       18           

Flag	Coverage Δ
frontend	85.52% <ø> (ø)

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