Fix mobile Safari viewport gestures and scrolling

[ael-dev3]

Summary

• keep the fixed app shell aligned with Safari's dynamic visible viewport
• resize the Realm renderer when iPhone browser chrome, keyboard, or visual viewport offsets change
• make internal panels use explicit vertical touch lanes and WebKit momentum scrolling
• prevent iOS Safari's small-input focus auto-zoom on mobile

Validation

• vitest run — 146 files, 1,483 tests passed
• TypeScript project build passed
• focused Realm/CSS contracts passed

This draft is intentionally scoped to mobile interaction behavior and targets main directly. No merge is requested, and no other PR was modified.

[ael-dev3]

Superseded by merged PR #72. The mobile Safari viewport, gesture, and scrolling fixes are included in the reviewed Alpha 0.3.12 integration.