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.
Move the channel-link button and View Options into a top safe-area inset
on tvOS so they are reachable with the remote, mirroring the Continue
Watching pattern. Wrap chrome and content in focus sections with a
default-focus namespace so initial focus lands on the first video. Hide
the duplicate in-content section header on tvOS, and add
scrollClipDisabled to VideoListContainer so focus scaling on rows is
not clipped at the scroll edges.
