Zenda-Cross/vega-providers — reverse-engineered prompt

Build me a TypeScript package for Vega app provider extensions. I want people to be able to add a new streaming content provider by creating a folder with a few simple files for the home page categories, item details, search and post lists, stream links, and optionally episodes for shows.

The package should define shared types for posts, metadata, streams, episode links, and a provider context with common web request helpers, HTML parsing, base URL lookup, and standard headers. Each provider should export predictable functions like getting posts for a filter and page, searching, getting metadata from a link, getting streams, and getting episodes when needed.

Please include a sample provider structure, a manifest, build scripts, and simple test or dev scripts so I can run a provider from the command line and check that catalog, search, metadata, episodes, and stream results work. Keep it easy for future contributors to copy a folder and make a new provider. Look up current docs online if you need to.