Problem

On Android 13, the status bar area in app pages is not fully immersive (appears as a solid bar instead of proper edge-to-edge blending).

Root Cause

Current implementation only calls WindowCompat.setDecorFitsSystemWindows(window, false) and does not fully use the recommended edge-to-edge API/styling strategy.

Scope

• Replace manual edge-to-edge setup with official enableEdgeToEdge(SystemBarStyle...)
• Keep status bar transparent and apply compatible nav bar scrim strategy
• Ensure activity-level unified entry point
• Set windowSoftInputMode="adjustResize" for insets/IME behavior consistency

Acceptance Criteria

• Android 13 status bar area is visually immersive and consistent with content
• No regressions on Android 14/15+
• Build passes for app module