Fix thread/list cwd filtering for Windows verbatim paths

[etraut-openai]

Addresses #17302

Problem: thread/list compared cwd filters with raw path equality, so resume --last could miss Windows sessions when the saved cwd used a verbatim path form and the current cwd did not.

Solution: Normalize cwd comparisons through the existing path comparison utilities before falling back to direct equality, and add Windows regression coverage for verbatim paths. I made this a general utility function and replaced all of the duplicated instance of it across the code base.