A feed is read up to 200 MB, not 50 (#357)

The Herd with Colin Cowherd's feed is 62 MB, its whole back catalogue, and had failed every check
since the 50 MB cap of #295 came in on 2026-10-19. The cap was there for an MP3 given as a feed;
200 MB still stops that, at four times the largest real feed seen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/directory/CHANGELOG.md

@@ -10,6 +10,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- A feed larger than 50 MB is checked again, up to 200 MB, where it was marked as failing (#357).
+
 ## [1.4.0] - 2026-10-23
 
 ### Fixed