Fixed Mobile app

Chat recorder cleanup and screenshot capture

Chat leaves audio-recorder disposal to Expo, and the screenshot build opens the composer without initializing recording hardware.

Chat no longer reads an audio recorder after Expo releases its native object during screen cleanup. Expo owns recorder disposal and stops active recording when that object is released.

The separate screenshot build uses empty attachment state in the real Chat composer. It does not create an audio recorder, and attempts to record or pick attachments fail locally. Regression tests cover recorder cleanup and screenshot isolation. Simulator capture still needs developer verification after rebuilding the screenshot app.