Enhanced transcription usability.

docs/Architecture.md

@@ -147,9 +147,13 @@ are the remaining M5 work; see `WorkBreakdown.md`.)
 3. The current segment is re-transcribed through the normal inference worker
    on a rolling basis (throttled, single-flight, latest-snapshot-wins) as
    *tentative* text; a committed segment gets one final pass and freezes.
-   `requestId` on the protocol messages correlates responses.
-4. Stopping flushes the segmenter, drains pending final passes, and yields a
-   normal transcript (text + absolute-timestamped chunks) in `TranscriptView`.
+   When inference runs slower than speech, queued committed segments are
+   batched into merged final passes (one Whisper window each, D-024) so the
+   backlog stays bounded. `requestId` on the protocol messages correlates
+   responses.
+4. Stopping flushes the segmenter, drains pending final passes (merged, with
+   a "N remaining segments" countdown in the UI), and yields a normal
+   transcript (text + absolute-timestamped chunks) in `TranscriptView`.
    Everything runs on-device; works offline like the file flow. Server-engine
    live input is a recorded future want (WorkBreakdown M7, D-016).