chore: take sphere-ui 0.1.43 so announcements render their body and markdown

[KruGoL]

Why

The announcement modal shipped in this app renders summary for a critical announcement and drops the body — everything an author wrote below the first paragraph never reaches the reader. That is fixed in sphere-ui 0.1.42 (unicity-sphere/sphere-ui#28), and 0.1.43 (unicity-sphere/sphere-ui#29) fixes the markdown around it: fenced code blocks used to render wearing inline code's pill inside an unstyled <pre>, pushing the modal wider than the viewport instead of scrolling; tables, blockquotes, hr, h4–h6 and images had no styling at all.

The lockfile here still pinned 0.1.41, so neither fix reached anyone regardless of the caret range — hence the explicit bump rather than waiting for an incidental npm install.

What changed

^0.1.43 plus the lockfile. No source changes: AnnouncementModal's props and behaviour are unchanged, the new AnnouncementModalCard export is additive, and react-markdown / remark-gfm are sphere-ui's own dependencies rather than peers, so nothing new is required here.

Verification

tsc --noEmit clean, vitest run — 833 passed (118 files).

Note on the jump

This app was on ^0.1.36 with its lock at 0.1.41, so the range moves seven versions at once. Everything in between is announcement or packaging work, none of it touching an API this app uses:

• 0.1.37 fade-in containing-block fix
• 0.1.38 shared announcement centre components
• 0.1.39 / 0.1.40 packaging (optional peers, ./announcements subpath)
• 0.1.41 discord icon key
• 0.1.42 / 0.1.43 the two fixes above