Delete declarations that Periphery reports unused on every platform that
compiles them (iOS, macOS, tvOS), including nine views used only by their
own previews. Platform-gated code still used on another platform, device-
only MPV render paths, migration models, CloudKit record names, App
Intents metadata and unused parameters are kept.
These views rendered video thumbnails without passing watchProgress, so the
progress bar was silently missing. Apply the existing pattern from
SubscriptionsView: maintain a watchEntriesMap and forward watchProgress(for:)
to VideoRowView/VideoCardView at each call site.
