Nova - Now with data analysis, PDF generation, and code explainer

NOVA is a terminal-first AI coding assistant and AI developer tool that helps developers debug code, fix runtime errors, automate workflows, understand codebases, and accelerate software development directly from the command line. This update adds data analysis with instant charts and summaries, PDF/document generation from a prompt, a code explainer for unfamiliar codebases, and a cleaner UI with scrollable work history.