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/featureFlags.test.ts

@@ -15,12 +15,12 @@ describe('featureFlags API', () => {
   it('fetches feature flags', async () => {
     const flags = await getFeatureFlags()
     expect(flags['feature.global.enabled']).toBe(true)
-    expect((client.get as any)).toHaveBeenCalled()
+    expect(vi.mocked(client.get)).toHaveBeenCalled()
   })
 
   it('updates feature flags', async () => {
     const resp = await updateFeatureFlags({ 'feature.global.enabled': false })
     expect(resp).toEqual({ status: 'ok' })
-    expect((client.put as any)).toHaveBeenCalledWith('/feature-flags', { 'feature.global.enabled': false })
+    expect(vi.mocked(client.put)).toHaveBeenCalledWith('/feature-flags', { 'feature.global.enabled': false })
   })
 })