The vi.mock('chart.js', ...) MockChart class was copy-pasted verbatim
between chart-canvas.spec.ts and overview.spec.ts. Extract it to
shared/chart-canvas/testing/mock-chart.ts and import it via
vi.hoisted(async () => import(...)) in each spec, since vi.mock's
factory is hoisted above regular imports and can't reference a
plain top-level import.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
