Add spoken spatial clock announcements with top-of-hour mode

docs/protocol-notes.md

@@ -39,6 +39,7 @@ This is a behavior guide for packet semantics beyond raw schemas.
 - `item_remove`: item deletion.
 - `item_action_result`: action success/failure and user-facing message.
 - `item_use_sound`: spatial one-shot sound on successful item use (if `useSound` configured).
+- `item_clock_announce`: ordered list of clock speech samples to play sequentially as spatial audio.
 - `item_piano_note`: broadcast piano note on/off with resolved instrument/envelope/spatial params.
 - `item_piano_status`: structured piano mode/record/playback state events for client runtime control.
 
@@ -50,6 +51,11 @@ This is a behavior guide for packet semantics beyond raw schemas.
 - `item_piano_status` carries machine-readable piano events (`use_mode_entered`, record/playback transitions).
 - `item_use_sound` contains absolute item world coordinates (`x`, `y`) and sound path.
   - For carried items, source coordinates resolve to the carrier's current position.
+- `item_clock_announce` contains:
+  - `itemId`
+  - `sounds`: ordered sample URLs (EL640 phrase parts)
+  - absolute source coordinates `x`, `y`
+  - generated by server for manual clock `use` and top-of-hour auto announce (when enabled)
 - `teleport_complete` contains absolute player world coordinates (`x`, `y`) at teleport landing.
 - Radio metadata (`params.stationName`, `params.nowPlaying`) is server-managed and delivered through normal `item_upsert` updates.
 - `item_piano_note` contains: