feat: add psql-style \cd command

[dcavalcante]

Add \cd to change pgxcli’s working directory, defaulting to the user’s home directory when no path is supplied.

Includes quoted and ~ paths, directory-only Tab completion and documentation

[balajz]

Please document the code, especially in areas where the logic might not be immediately clear, particularly where others might wonder, “Why is this done this way?” or “Why is this needed?”

[dcavalcante]

Please document the code, especially in areas where the logic might not be immediately clear, particularly where others might wonder, “Why is this done this way?” or “Why is this needed?”

done, lmk if anything is missing

[balajz]

Thank you for the contribution. I’d love to have tilde (~) completion, for example, when users type cd ~ and press Tab, it should complete to / (or \ on Windows).

[dcavalcante]

Implemented in f1642f8: \cd ~ now completes to ~/ (or ~\ on Windows), while retaining tilde shorthand. Added a regression test as well.