### `wai.live.events`: a signed, timeline-bound event track

- **The extension** ([live-events](extensions/live-events.md)) registers the record
  `wai.live.events`. Timed metadata, ad and chapter cues (with an SCTE 35-1
  `splice_info_section()` or an SCTE 35-2 message carried verbatim), chat, reactions,
  polls, markers, remote-control commands, captions with their machine-generation label,
  moderation decisions, take commitments and room lifecycle are each one `WEV1` record:
  signed by its principal, hash-chained per principal (`seq`, `prev`), stamped with the
  room clock and optionally anchored to one MoQ object. Its digest is SHA-256 over the
  record without the signature, and its signature is verified strictly (SPEC §7
  *Signatures*).
- **Policy and verification.** The event policy `WEP1` states the kinds a principal may
  send and the payload, text and rate bounds, every bound a default a room may change; the
  room grant of a later extension carries the same fields. A verifier refuses a record
  with a named reason (§9), and reports a delivery gap as a gap, never as corruption.
- **Polls** replay as `wai.feed.state` cells through `wai.world.sim.feed0` (`ADD_INT`):
  a tally is replay-equivalent, and a tally a poll's author states is checked.
- **Bindings**, field semantics only: an MSF event timeline over MoQ (`eventType`
  `urn:wai:event:1`, one track per principal, one-minute groups, a join set repeated at
  each group start), `EXT-X-DATERANGE` (`CLASS="science.transaction.wai.event"`,
  `X-WAI-EVENT`, with `SCTE35-OUT`/`-IN`/`-CMD` for cues), a version 1 `emsg`
  (`scheme_id_uri` `urn:wai:event:1`), a WebRTC data channel and a recording.
- **Reference and corpus.** `wai-rs` feature `live_events` (`src/live_events.rs`);
  `live-conformance/events/`, written from fixed seeds by `wai_live_events_vectors`, and
  checked by `tests/live_events.rs` and by `live-conformance/live_events_verify.py`, a
  second implementation that shares no code with `wai-rs`. The registry lists the record
  and its wire identifiers (`WEV1`, `WEP1`, `urn:wai:event:1`,
  `science.transaction.wai.event`, `X-WAI-EVENT`).

