[Feature Request] Enable Pure Dark Mode with Dynamic Colors

[Zhenghao-Wen]

1. Pure Dark mode is unavailable when Dynamic Colors is enabled. When the "Dynamic Colors" option is turned on, the "Pure Dark" (AMOLED black) theme option becomes unavailable. This is technically feasible, as many other Flutter-based apps with Material You design have successfully implemented Pure Dark mode alongside Dynamic Colors.

2. Visual inconsistency in Settings UI. When Dynamic Colors is enabled, the settings list items share the same background color as their containers, resulting in poor visual contrast and aesthetics.

Solution I'd like

1. Allow users to enable Pure Dark/AMOLED Black theme even when Dynamic Colors is active. The dynamic color palette should be applied to UI elements while using pure black for the background.

2. Improve the Settings UI contrast when Dynamic Colors is enabled by ensuring settings items have distinct background colors from their containers for better visual hierarchy.

Describe alternatives you've considered

• Currently, users must choose between Dynamic Colors and Pure Dark mode—they cannot have both.
• Manually disabling Dynamic Colors to use Pure Dark, but this defeats the purpose of having a hamonious color scheme.

Additional context

• App version: v0.10.6
• System version: Android 12