Add explicit vitest imports

tests/unit/bincount.spec.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import { binData } from '@/shared/charts/binCount';
 
 describe('binCount.ts', () => {

tests/unit/formatters.spec.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import { formatPercent, formatPrice, formatPriceCurrency } from '@/shared/formatters';
 
 describe('formatters.ts', () => {

tests/unit/timeformat.spec.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import {
   exportForTesting,
   timestampms,

tests/unit/timemath.spec.ts

@@ -1,3 +1,4 @@
+import { describe, it, expect } from 'vitest';
 import { roundTimeframe, ROUND_DOWN, ROUND_UP } from '@/shared/timemath';
 
 // 1651021200000 = 2022-04-27T11:05:00+00:00