Introduce an async `get_container` method across source implementations to fetch lightweight container metadata efficiently. Add the `futures` crate as a dependency to enable concurrent operations. Refactor the `browse` flow to short-circuit ephemeral IDs and delegate metadata resolution to `get_container`. Update the RadioFrance handler to scrape episode pages in parallel, bypassing limited RSS feeds and improving overall browsing performance.
Introduces the pmourlsource crate as a standard MusicSource that resolves HTTP/HTTPS URLs via a priority-ordered UrlHandler registry. Includes specialized handlers for Qobuz and Radio France alongside an SSRF-safe generic scraper supporting playlists, feeds, and HTML audio. Integrates with existing browse flows, REST endpoints, and Android Web Share targets while updating source capability flags to correctly route URL queries.
