Add Personal Access Token As An Alternative Authentication Option

[danielwrobert]

Due to the issue described in #314, the production application is no longer usable.

As a workaround, I've implemented the capability to connect to GitHub via a Personal Access Token. IIRC, this may have been a capability earlier on but this approach was removed in favor of the current authentication method.

As a starting point, I put together this PR so you can use the app via a local development instance by running yarn dev:desktop. This will open up the Electron application on your desktop and you can connect to GitHub with a Personal Access Token and use it.

IMPORTANT NOTE: Since I do not have familiarity with this code base, I used the agent AI feature in Cursor to work through getting this to a working state. After a few tries and a bit of guidance, I was able to get this up and running locally with the changes in this PR. That being said, there may be better ways to go about some of the implementation and I'm happy to make any preferred adjustments. My main goal was to have it working so I could, at the very least, spin up a local instance and use the app!