Steam's "Add a Non-Steam Game to My Library" entries carry no `appmanifest`, so
`scan_manifests` can't see them and they never appear in the streamed library.
Read each Steam account's binary `userdata/<id>/config/shortcuts.vdf` directly
(a binary KeyValues parse) to surface the user's own custom entries, plus their
grid artwork from `userdata/<id>/config/grid`. Best-effort: an unreadable or
absent shortcuts.vdf contributes nothing, and hidden shortcuts / duplicate
appids are dropped. Verified: clippy -D warnings + compile green on Linux.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>