The six inline catalog stats crammed into the tab row become one compact
"Stats" chip that reveals the numbers on hover — a new ChannelStatsPopover on
the AnchoredPopover hover mode, one icon-per-row (channels, recent synced, full
history, [ETA], my videos, quota left). Kept in the manager's own toolbar (the
header SyncStatus is global; these are channel-catalog figures). Retires the
local Stat helper + the now-unused formatEta import. i18n channels.stats.label
(HU+EN). Self-E2E'd: hover reveals the list. gate green (tsc/eslint-0/prettier).