feat(ui-react): add SpaceShare component and export; refactor(console…

[luisawatkins]

Extracts the space sharing UI from Console into @storacha/ui-react as a reusable SpaceShare component. Console now consumes this shared component to reduce duplication and centralize delegation management.

Changes

• Added SpaceShare component to @storacha/ui-react with support for:
  • Email sharing via client.shareSpace
  • DID delegation with UCAN archive download
  • Active and revoked delegation listing
  • Revocation management with status checks
• Exported SpaceShare from ui-react package index
• Updated Console's /space/[did]/share to use shared component
• Restored FullUploader to satisfy package exports

Checklist

• Component renders without Console-specific dependencies
• Email sharing creates and lists delegations
• DID input triggers UCAN download
• Revoked delegations display correctly
• Builds and type checks pass

Closes #597