Write again a stored item the feed now tells differently (#141)

"APPOFENIACS - A Technology Movie about Human Behavior" in Ain't It Cool News showed 66,170
characters: the feed's own HTTP headers and then the whole feed, tags stripped, and every other
item of the feed carried the text of the one before it. The publisher's feed had served it that
way, as only its XML could make a shift like that, and has since been fixed; ipx had read the
fixed feed and kept the broken text. Since 57ab419 (#96) a scan called record_entry only for a
guid it had not stored, so its UPDATE of title, description, image and duration was never
reached, and no correction, retitled episode or fixed length arrived.

Db::changed_items reads back what is stored for the items the feed lists, not the archive, and
names those it now gives a different title, text, artwork, length or number, a field it leaves
out counting as unchanged; the scan writes those again too. A corrected item keeps its read
state. A test serves a feed broken and then fixed from a socket of its own.

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

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- A publisher's correction to an item already in iPX, a retitled episode, mended text, new artwork or a fixed length, arrives on the next read. Since 0.9.1 an item kept what it first said: Ain't It Cool News's items each showed the text of the one before, long after the feed was fixed.
+
 ## [0.10.1] - 2026-10-05
 
 ### Fixed