Define the Kombu theme (Material 3 color scheme, typography, shapes) on top of the prototype

[MessiasLima]

Description

Depends on: Build the first visual prototype screens (placeholder destinations for every top-level tab).

Replace the temporary visuals with a real Material 3 theme: color scheme, typography, shapes, and spacing tokens.

• Scope and constraints
  • Create a theme/ package with Color.kt, Type.kt, Theme.kt, and Shape.kt.
  • Support light and dark color schemes.
  • Apply the theme to the existing prototype screens.
  • Pick a primary / accent color that matches the Kombu icon.
  • Keep it simple; no dynamic theming.

Scope

• In scope: theme files, light / dark palettes, typography, shapes, applying theme to existing screens.
• Out of scope: navigation, real features, icon assets.

Acceptance criteria

• MaterialTheme wraps the app.
• Light and dark themes render correctly on all platforms.
• Typography scale is defined and used on placeholder screens.
• Color scheme is referenced consistently (no hardcoded colors in screens).

Additional information

The theme must work across Android, iOS, JVM Desktop, JS, and WasmJS.