Add First-Run Interactive Config Setup

[squashd]

Task: Code an interactive prompt for initial setup to capture user preferences like text editor choice. This should kick in on the first run or when a config file is missing.

• Check for config file on startup.
• If not found, launch setup prompts.
• Save preferences to a config file.
• Include a --config flag to reinitiate setup anytime.

Purpose: Skip the manual config edit and get straight to work.