- The InnerTube enrichment takes ~30-45s; while videos are still undated the page
now shows a spinner 'Fetching upload dates from YouTube… your year-seasons will
fill in shortly' (reuses the episode-syncing indicator), which clears once the
years populate via the re-poll (or after the poll window).
- The Watchlist button on a channel was calling loadChannel() on follow — a full
re-fetch + scroll-to-top that read as a page refresh. Now it just flips the
button in place (data.following + renderActions), like unfollow already did.
