Epic: Mobile Experience

Goal: Bring the iOS and Android apps to feature parity with web, starting with navigation and sign-in.

Why it matters: Mobile is where most sessions start and where the interface is currently weakest.

Success looks like:

• Shared navigation model across both mobile apps
• Spec and prototype signed off before any implementation starts
• No mobile-only regressions in the sign-in flow

Out of scope for now: tablet-specific layouts, offline mode.