Chat emits file refs as `[label](#media:<encoded path>)`, but the Artifacts collector classified the raw href and dropped it. Decode those hrefs before looksLikeArtifact so Windows and POSIX paths, image markdown, and explicit tool artifact keys are collected. Legacy MEDIA: tags and plain URLs are unchanged. Same decode as pull 88158; that patch did not apply cleanly. Fixes #88084 Co-authored-by: SayHell0W0rld <18085695+SayHell0W0rld@users.noreply.github.com>