Need to read current ssh-config file into structured data

This should be OK to read total nonsense, perhaps kicking up a fuss if it's clearly not an ssh config file (consider the user accidentally opening their private key, panicking, and saving a valid ssh-config over it). If it's total nonsense the next step is to mark entries and lines as invalid.

No file or test is named; start by locating the SSH-config parsing entry point and reviewing how configuration data is represented. Define the expected behavior for valid configs, total nonsense, and accidentally opened private keys, then verify that current SSH config content becomes structured data and invalid entries or lines can be identified.

Written by the indexing model from the issue text.