fix: StakeManager migration fixes and certora rules

[0x-r4bbit]

This is an alternative to #47 Basically, the changes in the commit are supposed to be the same, however it has #53 as a base as opposed to #58

@3esmit hope this helps you moving forward

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• [ ] Added natspec comments?
• [ ] Ran forge snapshot?
• [ ] Ran pnpm lint?
• [ ] Ran forge test?
• [ ] Ran pnpm verify?

[0x-r4bbit]

Rebased this one on top of latest develop as #53 has been merged.

Waiting for CI then I'll merge this one