Improve Hangout section empty state and meeting actions

[SahilKumar75]

Summary

Polish the Hangout section so users see a clearer empty state and practical meeting actions before full backend scheduling is available.

Scope

• Improve the empty state for no active or upcoming hangouts.
• Add clear actions for creating, joining, or copying meeting details where the current app model supports it.
• Keep layout consistent with existing Sentri app screens.
• Avoid unrelated app redesign.

Acceptance Criteria

• Hangout empty state is understandable on mobile and web-sized views.
• Meeting action buttons are clear and do not overlap text.
• The PR includes visual verification or screenshots.
• Expo app startup or web export is verified.