While the keyboard is open on a phone, the camera shrinks to a 120 px mini player and returns when it closes #287

From #51.

Done:

• [ ] When the visual viewport shrinks for the keyboard, the camera becomes a 120 px tall mini player. It returns to full size when the keyboard closes, with no layout jump in the chat list.
• [ ] Playwright at 390x844 with the keyboard emulated: the camera is 120 px tall and the composer is visible.
• [ ] forge.json untouched. bun --cwd Software/so101 test passes.