Motivation

• Provide an opinionated, token-driven mobile theme tuned for Android/Material mobile surfaces and controls that can be opt‑in via data-theme="android".
• Make the new theme discoverable and easy to try in the demo by adding an in-demo theme picker.
• Export the new theme file so consumers can import it from the package.

Description

• Adds a new theme file at src/themes/android-mobile.css implementing light/dark token overrides and mobile-focused component styles for surfaces, buttons, inputs, lists, and selection controls.
• Exposes the theme in the package exports and includes src/themes in the published files via edits to package.json (./themes/android-mobile.css and adding src/themes to files).
• Adds a demo theme switcher component demo/src/theme-switcher.tsx, wires it into the demo navigation in demo/src/nav.tsx, and imports the theme in demo/src/style.css so the demo can opt into the Android theme.
• Adds demo CSS for the theme switcher UI in demo/src/style.css and documents the new theme in docs/pages/theming.md with usage instructions.

Testing

• Ran the project test suite with pnpm test (runs vitest run), and the existing tests completed successfully.

Codex Task