Add mobile browser parity and release hardening

[bigdestiny2]

Summary

• add major-browser page actions across React Native, SwiftUI, and Jetpack Compose
• complete the mobile tab, screen, search/naming, security, content-shield, plugin, identity, and QVAC parity work in the candidate
• align Android signing across both shells and CI, remove native API deprecations, refresh generated bundles, and add current release evidence

Verification

• npm test: 566/566
• npm audit --audit-level=high: pass (0 high/critical; 9 moderate Expo build-tool advisories remain)
• bundle generation: compatibility and native bundles pass
• release preflight: 15 pass, 0 warn, 4 expected production-authority blockers; report verifier accepts no unexpected findings
• Android: debug Kotlin compile plus lint-vital, R8, release APK, and release AAB pass
• native SwiftUI: Debug and Release generic-device builds pass
• generated Expo iOS: 99-target Release generic-device build passes

The four soft-preflight blockers are intentionally limited to real production signing and recorded iOS/Android store validation; no credentials or validation markers are fabricated in source.