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/components/RemoteServerForm.tsx

@@ -135,7 +135,10 @@ export default function RemoteServerForm({ server, onSubmit, onCancel }: Props)
                 min={1}
                 max={65535}
                 value={formData.port}
-                onChange={e => setFormData({ ...formData, port: parseInt(e.target.value) })}
+                onChange={e => {
+                  const v = parseInt(e.target.value)
+                  setFormData({ ...formData, port: Number.isNaN(v) ? 0 : v })
+                }}
                 className="w-full bg-gray-900 border border-gray-700 rounded-lg px-4 py-2 text-white focus:outline-none focus:ring-2 focus:ring-blue-500"
               />
             </div>