fix: Handle repurcissions for remote support

[epage]

211 and #212 built up support for #12 but there were some corner cases that weren't handled

• main was not being updated when pulling
• main showed as unprotected branch on a protected commit
• We weren't puling from the users selected remote
• We might push main which is good for a fork model but not for a central model

To address these, small tweaks were made that also streamline the code, making things more principled based which should hopefully make it clearer.

The downside is that we've gone back to main always being protected rather than allowing it to be unprotected and rebasing it.