iOS: Dashboard, inbox filters, and team roles

The iOS app now has a dashboard, proper inbox filtering, and team management. Getting closer to full feature parity with the web app.

What's new

• A dashboard tab with area-fill charts, response time metrics, and a peak timing heatmap.
• Filter pills at the top of the inbox to quickly narrow conversations by status or assignee.
• Full team role management with owner and viewer roles, plus member search.
• On-device conversation summaries generated locally without a server round-trip.
• Haptic feedback, grouped bubble styles, and deterministic avatar colors throughout the app.