Refactoring follow-ups

Keeping this issue open for now for the initial refactoring follow-ups. The current focus is just on getting this extracted from our core repo. Afterwards I'd like to start refactoring the core, maybe introducing better abstractions to allow easier modification by users of the lib.

Start by reviewing how this extracted snapshot testing library relates to the core repository and identify the remaining refactoring follow-ups. The issue mentions possible abstractions for easier modification by library users, but names no files, tests, or specific completion criteria; clarify the scope before making changes.

Written by the indexing model from the issue text.