Moves the Zap button and Zap statistics from the message thread header to the message composer area, adjacent to the Send button. Refactors the Zap interface creation logic into a standalone component `ZapInterface.js` to decouple it from `MessageThread.js`. Updates `Composer.js` to support an optional `onZap` handler and `zapStats` prop, rendering the button with an icon-only style and the stats pill reusing the existing CSS class. Updates `AppShell.js` to orchestrate the Zap interface display and pass the necessary statistics.
Moves the Zap button from the message thread header to the message composer area, adjacent to the Send button. Refactors the Zap interface creation logic into a standalone component `ZapInterface.js` to decouple it from `MessageThread.js`. Updates `Composer.js` to support an optional `onZap` handler and renders the button with an icon-only style matching the video player's accent interaction. Updates `AppShell.js` to orchestrate the Zap interface display.
- Implement mobile view state management (`list` vs `thread`) in `ProfileModalController`.
- Update `AppShell` to apply `data-dm-view` attribute for CSS toggling.
- Update `MessageThread` to render a "Back" button on mobile.
- Add CSS rules to hide/show sidebar and thread panels based on mobile view state.
- Ensure desktop layout remains split-pane.