Tildy name flashes on startup

[thedadams]

When starting the app with a thread using a custom assistant, the name of the assistant will briefly flash as "Tildy" and then switch to the correct name.

The "Tildy" name should not flash and the correct name should be used.

[thedadams]

PR: #337

[thedadams]

To reproduce this issue:

• Ensure your top thread is with a custom tool, not Tildy
• Press Cmd-r to refresh the page
• You should see Tildy flash at the top of the screen before the name of the assistant shows up

With the proposed changes, that should not happen any longer.

[sangee2004]

Tested with electron build 97e615c58

This issue is not seen anymore.