Externalize Hero release badge text for i18n

## Summary
Externalize the Hero release badge text currently hardcoded in `landing-page/src/components/Hero.tsx` (for example, `v1.0.4 IS OUT NOW`) into the landing page's i18n resource files.

## Rationale
The badge is user-visible content and should be localized consistently with the rest of the landing page.

## Affected area
- `landing-page/src/components/Hero.tsx`
- The relevant locale/resource files used by the landing page

## Required changes
- Add an appropriately named translation key for the release badge to every supported locale resource.
- Render that key from `Hero` using the project's established i18n mechanism.
- Preserve the current displayed English text.

## Acceptance criteria
- `Hero` no longer contains the release badge text as a hardcoded JSX string.
- All relevant locale resources contain the new key.
- The badge continues to display `v1.0.4 IS OUT NOW` in the default English locale.

Requested by: @kpj2006

Backlinks:
- PR: https://github.com/AOSSIE-Org/SocialShareButton/pull/194
- Review discussion: https://github.com/AOSSIE-Org/SocialShareButton/pull/194#discussion_r3610048350