## Why
Footer updates and transcript animation can trigger redraws before more audio arrives, consuming peaks too early and adding spurious quiet samples. Old peaks also linger in the meter after a channel becomes quiet.
## What changed
- Sample microphone and speaker peaks at most once every 100 ms, preserving accumulated peaks on early redraws and scheduling the next sampling frame.
- Clear each channel's meter history on its first quiet sample without clearing the other channel.
## Testing
Add regression tests for early redraw scheduling, peak preservation, independent channel silence, delayed sampling, and sampling after a conversation reset. Snapshot the meters at wide and narrow widths and after each channel becomes quiet.
GitOrigin-RevId: d7b116af2c099a2eaeb6db0d66bca93b230db970
Benjamin Carlsson
9a3af22d01