feat(soundboard): shared room/space packs (like emoji/stickers), grid picker, management

Soundboard v2 — a near-parallel of the custom-emoji image-pack system for
in-call audio clips.

- Data model: 3-tier packs mirroring MSC2545 — room/space pack (state event
  io.lotus.soundboard, inherited by child rooms via parent-space aggregation),
  global refs (io.lotus.soundboard_rooms), and the personal pack
  (io.lotus.soundboard account data; the v1 flat-list content is migrated to the
  pack shape on read). New plugins/soundboard/ (readers, SoundboardPack, utils) +
  hooks/useSoundboardPacks (useRelevantSoundboardPacks = user U global U room,
  deduped). Unit-tested (migration + slug).
- Management: reusable SoundboardPackEditor (name + emoji + per-clip volume +
  delete + upload + batched save), power-level-gated for room packs like emoji
  packs; a Soundboard page wired into Room + Space settings.
- In-call: CallSoundboard rewritten as a Discord-style grid grouped by pack
  (emoji + name tiles), sourcing room+parent-space U personal clips; a Manage
  toggle embeds the editors; per-clip volume x master volume on playback.
- Spam guard: host gates on a playing key (fork enforces one clip at a time).
- Control bar: Mute-Screenshare moved next to the Screenshare button.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/types/matrix/accountData.ts

@@ -10,9 +10,12 @@ export enum AccountDataEvent {
   PoniesUserEmotes = 'im.ponies.user_emotes',
   PoniesEmoteRooms = 'im.ponies.emote_rooms',
 
-  // [P5-15] Personal, uploadable in-call soundboard clips (synced across
-  // devices like custom emoji/sticker packs).
+  // [P5-15] Personal soundboard pack (synced across devices). v2 content is a
+  // SoundboardContent pack ({pack, clips}); v1 was {clips: [...]} (migrated on read).
   LotusSoundboard = 'io.lotus.soundboard',
+  // [P5-15 v2] Global refs: room soundboard packs the user enabled everywhere
+  // (mirrors im.ponies.emote_rooms).
+  LotusSoundboardRooms = 'io.lotus.soundboard_rooms',
 
   // [P4-1] Per-thread notification mode overrides (All/Mentions/Mute) plus the
   // global default behavior for threads.

src/types/matrix/room.ts

@@ -42,6 +42,9 @@ export enum StateEvent {
   PowerLevelTags = 'in.cinny.room.power_level_tags',
   LotusVoiceLimit = 'io.lotus.voice_limit',
   LotusRoomQuality = 'io.lotus.room_quality',
+  // [P5-15 v2] Room/Space soundboard pack (mirrors PoniesRoomEmotes). Per
+  // state-key, aggregated with parent-space packs like custom emoji.
+  LotusSoundboardRoom = 'io.lotus.soundboard',
 }
 
 export enum MessageEvent {