Google News RSS feeds report every article as coming from
"news.google.com" because the source was extracted from the feed URL
rather than the individual article. This adds a multi-strategy
resolver that extracts the real publisher name via:
1. SimplePie <source> element (Google News provides this)
2. Title suffix parsing ("Headline - Source" format)
3. HTTP HEAD redirect resolution as a fallback
Also adds a one-click "Fix Article Sources" backfill button on the
settings page to correct existing articles in the database.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>