Slow portal creation UI feedback - should show loading state

[nikomatsakis]

Expected Behavior:
When clicking the '+' button to create a new portal, the sidebar should immediately show a new portal entry with a loading indicator (hourglass/spinner) while the portal is being initialized in the background.

Actual Behavior:
When clicking the '+' button, there's a long delay before the new portal appears in the sidebar. During this time, there's no visual feedback that anything is happening, making it unclear if the click registered or if the system is working.

Steps to Reproduce:

1. Open theoldswitcheroo app
2. Click the '+' button to create a new portal
3. Observe that the sidebar doesn't update immediately
4. Wait several seconds for the new portal to appear

Technical Details:
The delay is caused by background operations (SSH connection, directory creation, git clone, etc.) that happen before the portal appears in the UI. The UI should show immediate feedback and update the portal state as initialization progresses.