Rework the share dialog into two clear modes and add the public /watch player page:
- ShareDialog: (A) 'Share with a user' — autocomplete picker over registered users (was a blind
email box that 404'd on non-users); (B) 'Share a link' — create/list/copy/revoke public links
with allow-download toggle, optional expiry (1/7/30d), optional password; per-link view count.
- WatchPage: standalone login-free player at /watch/<token> (routed in main.tsx like /privacy),
self-contained mini-i18n (en/hu/de by browser language); password gate → unlock → play; shows a
Download button only when the link allows it.
- api: ShareLink/ShareRecipient types + link CRUD + recipients; share i18n (en/hu/de).
Verified end-to-end in a real browser: user picker, link create, public playback, stream-only vs
downloadable, password gate + unlock, no console errors.
