Strike a bell on every beat of the pitch deck.

Strike ONE bell sound on every beat of the deck's bell beat grid, frame-exact, as one lane on its audio timeline — or change the lane. The sound is assetId (a My Library sound effect), sound: { fromJobId } (another deck's bell of the same project, exactly as it struck there: the same bell as v2), or prompt (words for one to be made with the sound-effect generator and banked in My Library; label, durationSeconds), or — on a change — the lane's own. every 1 (every beat, default) or 2 (every 2nd beat); fromSeconds/toSeconds in seconds of the master (null: its first/last frame, the default); skipSceneIndexes the parts it stays out of (black interludes, chapters, the title sequence); accent (the intros and the title louder, default true); level 0–1 (0.12: every bell is struck levelled to a -1 dBFS peak, and 0.12 sits a few dB under a laid score); duckUnderVoice (default true: it ducks under the spoken lines like the score). Fields left out keep the lane's; an unknown field is refused by name. Free: nothing is rendered again — a deck in review or finished re-stitches its master for its sound (reassembling), a sketch waiting for its master is mixed again with the bell (sketchRemixing), and a score to picture composed with a lane leaves room for the struck bell (no bell of its own, nothing on the downbeat). Refused with a 409 when the deck has no bell beat grid. Requires Idempotency-Key. Scope: story:write.