Improve UI responsiveness during startup

[stevenlei]

Problem

The willSelect method in teaBASE.m was performing several heavy operations synchronously on the main thread, which could cause UI blocking during startup.

Solution

Moved heavy operations to background queues while ensuring UI updates happen on the main thread. The changes include:

• Using dispatch_group to coordinate multiple async operations
• Moving heavy operations (updateSSHStates, updateVersions, etc.) to background queues
• Ensuring UI updates occur on the main thread
• Initially disabling UI elements and enabling them as their data becomes available

Benefits

• Improved UI responsiveness during startup