Migrate test suite from Jest to Vitest

[Copilot]

Migrates the entire test suite to Vitest, removing Jest dependencies and updating Angular configuration to use the native @angular/build:unit-test builder.

Changes

Dependencies

• Removed: jest, jest-environment-jsdom, @types/jest, ts-jest
• Added: vitest@^4.0.8, @vitest/browser@^4.0.8 (Angular 21 compatibility)

Configuration

• Updated angular.json: @angular-devkit/build-angular:jest → @angular/build:unit-test
• Removed libs/core/jest.config.js and libs/components/jest.config.js
• Cleaned up tsconfig.spec.json (removed ts-jest config)

Test Files (22 files)

All spec files updated to use explicit Vitest imports and APIs:

// Before
import { TestBed } from '@angular/core/testing'

describe('MyService', () => {
  let spy: jest.SpyInstance
  
  beforeEach(() => {
    spy = jest.spyOn(service, 'method')
  })
  
  test('should work', () => {
    const mock = jest.fn()
    expect(mock).toHaveBeenCalled()
  })
})

// After
import { TestBed } from '@angular/core/testing'
import { describe, it, expect, beforeEach, vi } from 'vitest'

describe('MyService', () => {
  let spy: ReturnType<typeof vi.spyOn>
  
  beforeEach(() => {
    spy = vi.spyOn(service, 'method')
  })
  
  it('should work', () => {
    const mock = vi.fn()
    expect(mock).toHaveBeenCalled()
  })
})

All jest.* → vi.* and test() → it() throughout codebase.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>update tests to vitest</issue_title>
<issue_description>- [ ] remove all jest deps

• install vitest
• use @angular/build:unit-test in angular.json for the test architext and configure it for vitest
• use imports in all tests (spec files) for describe, it, expect and vi instead of global types
• refactor tests use run with vitest</issue_description>

<agent_instructions>name the branch copilot/#67-update-tests-to-vitest</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes update tests to vitest #67

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