Audience: macOS app contributors. Goal: keep the voice overlay predictable when wake-word and push-to-talk overlap.
### Current intent
- If the overlay is already visible from wake-word and the user presses the hotkey, the hotkey session *adopts* the existing text instead of resetting it. The overlay stays up while the hotkey is held. When the user releases: send if there is trimmed text, otherwise dismiss.
- Wake-word alone still auto-sends on silence; push-to-talk sends immediately on release.
- Overlay sessions now carry a token per capture (wake-word or push-to-talk). Partial/final/send/dismiss/level updates are dropped when the token doesn’t match, avoiding stale callbacks.
- Push-to-talk adopts any visible overlay text as a prefix (so pressing the hotkey while the wake overlay is up keeps the text and appends new speech). It waits up to 1.5s for a final transcript before falling back to the current text.
- Chime/overlay logging is emitted at `info` in categories `voicewake.overlay`, `voicewake.ptt`, and `voicewake.chime` (session start, partial, final, send, dismiss, chime reason).