fix(player-offline): replace broken <1> Trans placeholder with JSX bolding master
The user-offline-message i18n key uses Fluent's numeric placeholder syntax (<1>...</1>). With i18next-fluent + Trans, this didn't render — the literal '<1>' showed up in the rendered output instead of being replaced with the bolded handle. The combination of Fluent selectors and numeric placeholders through i18next-fluent doesn't round-trip cleanly. Switched to plain JSX composition: the message is inline in the component with a <span className='font-semibold'> around the handle. We lose the source/handle as a localized interpolation, but the offline copy is small and the screenshot the user pointed at is the canonical text anyway. Also: the recommendation case reads 'they recommend' and the no-recommendation case reads 'is offline right now. Check back later.' — closer to the Twitch reference text.