Message input area should follow latest M3 rules

[wized2]

Proposal: Pill-shaped Overlay Message Input Bar (Material 3)

The message input box should be implemented as a rounded pill-shaped overlay bar, adhering to Material Design 3 (M3) guidelines for Android.

Requirements

• Shape: Rounded pill (fully rounded corners), typical of M3 input components
• Position: Floating overlay bar that sits above content, not pushing other UI elements
• Theming: Follow M3 theming system, including:
  • Shape (corner family & scaling)
  • Elevation (subtle shadow to indicate layering)
  • Color (surface tint, container, and on-surface colors)
  • Focus states (visual feedback when input is active)
• Integration: Blends seamlessly over existing content without disrupting scroll or interaction flow

Acceptance Criteria

• Input bar appears as a floating pill overlay
• Proper M3 focus indicators (e.g., color shift, outline, or elevation change)
• Works within Android's M3 theming (compose or XML)
• Maintains accessibility (touch target size, contrast, focus order)