Full example app exercising discovery, exchange, invites, map sharing

[gmaclennan]

Context

Milestone-doc nice-to-have: a fuller apps/example that surfaces the features that are hard to cover with automated tests — peer discovery, data exchange, project invites, and map sharing — so they can be exercised manually on real devices.

Scope (to refine)

• Screens/flows for discovery + invite + exchange + map sharing on top of the existing example app.
• Useful as a manual pre-release smoke surface and a living integration reference for host apps.

Complements the e2e/Maestro automation (which covers the automatable surface).