feat(tests): add comprehensive tests for ProxyHosts and Uptime components

- Introduced isolated coverage tests for ProxyHosts with various scenarios including rendering, bulk apply, and link behavior.
- Enhanced existing ProxyHosts coverage tests to include additional assertions and error handling.
- Added tests for Uptime component to verify rendering and monitoring toggling functionality.
- Created utility functions for setting labels and help texts related to proxy host settings.
- Implemented bulk settings application logic with progress tracking and error handling.
- Added toast utility tests to ensure callback functionality and ID incrementing.
- Improved type safety in test files by using appropriate TypeScript types.

frontend/src/api/__tests__/backups.test.ts

@@ -0,0 +1,34 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import client from '../../api/client'
+import { getBackups, createBackup, restoreBackup, deleteBackup } from '../backups'
+
+describe('backups api', () => {
+  beforeEach(() => {
+    vi.restoreAllMocks()
+  })
+
+  it('getBackups returns list', async () => {
+    const mockData = [{ filename: 'b1.zip', size: 123, time: '2025-01-01T00:00:00Z' }]
+    vi.spyOn(client, 'get').mockResolvedValueOnce({ data: mockData })
+    const res = await getBackups()
+    expect(res).toEqual(mockData)
+  })
+
+  it('createBackup returns filename', async () => {
+    vi.spyOn(client, 'post').mockResolvedValueOnce({ data: { filename: 'b2.zip' } })
+    const res = await createBackup()
+    expect(res).toEqual({ filename: 'b2.zip' })
+  })
+
+  it('restoreBackup posts to restore endpoint', async () => {
+    const spy = vi.spyOn(client, 'post').mockResolvedValueOnce({})
+    await restoreBackup('b3.zip')
+    expect(spy).toHaveBeenCalledWith('/backups/b3.zip/restore')
+  })
+
+  it('deleteBackup deletes backup', async () => {
+    const spy = vi.spyOn(client, 'delete').mockResolvedValueOnce({})
+    await deleteBackup('b3.zip')
+    expect(spy).toHaveBeenCalledWith('/backups/b3.zip')
+  })
+})