Operator-reported: selecting a different item in the content window left the
context-surface banner showing the previous item's image. Root cause: detail
views are reused, not remounted, and useBannerFallback kept primaryIndex/
stage/apiUrl alive across the prop change — once stage hit 'api' or 'done' it
never re-evaluated. Reset is keyed on title + the primary URL set, with a
generation guard so an in-flight fetch for the old item cannot stamp its
artwork onto the new one. Heals Film/TVSeries/Book detail at once; 3
regression tests pin it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
