feat: audio room stage with NIP-53 presence (kind 10312)

Phase 2 of the Clubhouse/nests integration: when the live-activity
channel screen is opened on a kind 30312 MeetingSpaceEvent, render an
audio-room "stage" above the chat that shows host/speaker/audience
avatars and exposes hand-raise + mute toggles backed by NIP-53 kind
10312 presence events.

Quartz:
- New MutedTag (`["muted","1"|"0"]`) and `muted()` builder helper for
  MeetingRoomPresenceEvent.
- New MeetingRoomPresenceEvent.build() overload that accepts a 30312
  MeetingSpaceEvent root (matching the existing 30313 overload) and
  optionally encodes hand-raise + mute flags in one call.

Amethyst:
- AudioRoomStage composable: filters participants from the 30312 event
  into hosts / speakers / audience, renders avatars, and publishes
  presence on enter + every 30 s while composed (on dispose it pushes
  one final lowered-hand presence so peers drop us before timeout).
- ChannelView wires AudioRoomStage in next to ShowVideoStreaming; the
  latter is a no-op for non-30311 events so non-audio rooms are
  unaffected.

No audio is captured yet — the mic toggle is a Nostr-only signal
until Phase 3 brings the MoQ/WebTransport transport.

https://claude.ai/code/session_013nVLALALKaHVgHm9u5Cg8D

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/audiorooms/room/AudioRoomStage.kt

@@ -0,0 +1,258 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.audiorooms.room
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyRow
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Mic
+import androidx.compose.material.icons.filled.MicOff
+import androidx.compose.material.icons.filled.PanTool
+import androidx.compose.material.icons.outlined.PanTool
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.FilledIconButton
+import androidx.compose.material3.FilledTonalIconButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButtonDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.nip53LiveActivities.LiveActivitiesChannel
+import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
+import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.Size35dp
+import com.vitorpamplona.amethyst.ui.theme.Size40dp
+import com.vitorpamplona.amethyst.ui.theme.StdHorzSpacer
+import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingSpaceEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.MeetingRoomPresenceEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags.ParticipantTag
+import com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags.ROLE
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+
+/**
+ * Clubhouse-style audio-room "stage" rendered in place of the video player when
+ * the underlying activity is a NIP-53 kind 30312 [MeetingSpaceEvent].
+ *
+ * Phase 2 scope: shows host + speaker + audience avatars and lets the local user
+ * publish their kind 10312 presence (with hand-raise + mute flags) on relays.
+ * The mic toggle is a Nostr-only signal at this point — actual audio capture
+ * arrives in Phase 3 with the MoQ/WebTransport transport.
+ */
+@Composable
+fun AudioRoomStage(
+    baseChannel: LiveActivitiesChannel,
+    accountViewModel: AccountViewModel,
+) {
+    LoadAddressableNote(baseChannel.address, accountViewModel) { addressableNote ->
+        addressableNote ?: return@LoadAddressableNote
+        val event = addressableNote.event as? MeetingSpaceEvent ?: return@LoadAddressableNote
+        AudioRoomStageContent(event, accountViewModel)
+    }
+}
+
+@Composable
+private fun AudioRoomStageContent(
+    event: MeetingSpaceEvent,
+    accountViewModel: AccountViewModel,
+) {
+    val participants = remember(event) { event.participants() }
+    val hosts = remember(participants) { participants.filter { it.role.equals(ROLE.HOST.code, true) } }
+    val speakers = remember(participants) { participants.filter { it.role.equals(ROLE.SPEAKER.code, true) } }
+    val audience =
+        remember(participants) {
+            participants.filter {
+                !it.role.equals(ROLE.HOST.code, true) &&
+                    !it.role.equals(ROLE.SPEAKER.code, true)
+            }
+        }
+
+    var handRaised by rememberSaveable(event.address().toValue()) { mutableStateOf(false) }
+    var muted by rememberSaveable(event.address().toValue()) { mutableStateOf(true) }
+    val scope = rememberCoroutineScope()
+    val account = accountViewModel.account
+
+    // Publish initial presence on enter and refresh every PRESENCE_REFRESH_MS while composed.
+    LaunchedEffect(event.address().toValue(), handRaised, muted) {
+        publishPresence(account, event, handRaised, muted)
+        while (isActive) {
+            delay(PRESENCE_REFRESH_MS)
+            publishPresence(account, event, handRaised, muted)
+        }
+    }
+
+    // Best-effort "leave" — re-publish a CLOSED presence so peers see us drop sooner
+    // than the 30 s heartbeat would otherwise allow.
+    DisposableEffect(event.address().toValue()) {
+        onDispose {
+            scope.launch(Dispatchers.IO) {
+                runCatching { publishPresence(account, event, handRaised = false, muted = true) }
+            }
+        }
+    }
+
+    Card(
+        modifier = Modifier.fillMaxWidth().padding(8.dp),
+        shape = RoundedCornerShape(12.dp),
+        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceVariant),
+    ) {
+        Column(modifier = Modifier.padding(12.dp)) {
+            event.room()?.let {
+                Text(
+                    text = it,
+                    style = MaterialTheme.typography.titleMedium,
+                )
+            }
+            event.summary()?.let {
+                Text(
+                    text = it,
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+
+            if (hosts.isNotEmpty() || speakers.isNotEmpty()) {
+                StagePeopleRow(
+                    label = stringRes(R.string.audio_room_stage),
+                    people = hosts + speakers,
+                    avatarSize = Size40dp,
+                    accountViewModel = accountViewModel,
+                )
+            }
+
+            if (audience.isNotEmpty()) {
+                StagePeopleRow(
+                    label = stringRes(R.string.audio_room_audience),
+                    people = audience,
+                    avatarSize = Size35dp,
+                    accountViewModel = accountViewModel,
+                )
+            }
+
+            Row(
+                modifier = Modifier.fillMaxWidth().padding(top = 8.dp),
+                horizontalArrangement = Arrangement.End,
+                verticalAlignment = Alignment.CenterVertically,
+            ) {
+                FilledTonalIconButton(onClick = { handRaised = !handRaised }) {
+                    Icon(
+                        imageVector = if (handRaised) Icons.Filled.PanTool else Icons.Outlined.PanTool,
+                        contentDescription =
+                            stringRes(
+                                if (handRaised) R.string.audio_room_lower_hand else R.string.audio_room_raise_hand,
+                            ),
+                    )
+                }
+                StdHorzSpacer
+                FilledIconButton(
+                    onClick = { muted = !muted },
+                    colors =
+                        if (muted) {
+                            IconButtonDefaults.filledIconButtonColors()
+                        } else {
+                            IconButtonDefaults.filledIconButtonColors(
+                                containerColor = MaterialTheme.colorScheme.error,
+                                contentColor = MaterialTheme.colorScheme.onError,
+                            )
+                        },
+                ) {
+                    Icon(
+                        imageVector = if (muted) Icons.Filled.MicOff else Icons.Filled.Mic,
+                        contentDescription =
+                            stringRes(
+                                if (muted) R.string.audio_room_unmute else R.string.audio_room_mute,
+                            ),
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun StagePeopleRow(
+    label: String,
+    people: List<ParticipantTag>,
+    avatarSize: androidx.compose.ui.unit.Dp,
+    accountViewModel: AccountViewModel,
+) {
+    Column(modifier = Modifier.padding(top = 8.dp)) {
+        Text(
+            text = label,
+            style = MaterialTheme.typography.labelMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        LazyRow(
+            modifier = Modifier.fillMaxWidth().padding(top = 4.dp),
+            horizontalArrangement = Arrangement.spacedBy(6.dp),
+        ) {
+            items(items = people, key = { it.pubKey }) {
+                ClickableUserPicture(
+                    baseUserHex = it.pubKey,
+                    size = avatarSize,
+                    accountViewModel = accountViewModel,
+                )
+            }
+        }
+    }
+}
+
+private const val PRESENCE_REFRESH_MS = 30_000L
+
+private suspend fun publishPresence(
+    account: com.vitorpamplona.amethyst.model.Account,
+    event: MeetingSpaceEvent,
+    handRaised: Boolean,
+    muted: Boolean,
+) {
+    runCatching {
+        account.signAndComputeBroadcast(
+            MeetingRoomPresenceEvent.build(
+                root = event,
+                handRaised = handRaised,
+                muted = muted,
+            ),
+        )
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/nip53LiveActivities/ChannelView.kt

@@ -35,6 +35,7 @@ import com.vitorpamplona.amethyst.ui.feeds.WatchLifecycleAndUpdateModel
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.note.LoadLiveActivityChannel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.audiorooms.room.AudioRoomStage
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.feed.RefreshingChatroomFeedView
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.dal.ChannelFeedViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.datasource.ChannelFilterAssemblerSubscription
@@ -129,6 +130,7 @@ fun LiveActivityChannelView(
                     .weight(1f, true),
         ) {
             ShowVideoStreaming(channel, accountViewModel)
+            AudioRoomStage(channel, accountViewModel)
             LiveStreamTopZappers(channel, accountViewModel, nav)
             LiveStreamGoalHeader(channel, accountViewModel, nav)
             RefreshingChatroomFeedView(

amethyst/src/main/res/values/strings.xml

@@ -489,6 +489,12 @@
     <string name="follow_packs">Follow Packs</string>
     <string name="live_streams">Live Streams</string>
     <string name="audio_rooms">Audio Rooms</string>
+    <string name="audio_room_stage">Stage</string>
+    <string name="audio_room_audience">Audience</string>
+    <string name="audio_room_raise_hand">Raise hand</string>
+    <string name="audio_room_lower_hand">Lower hand</string>
+    <string name="audio_room_mute">Mute</string>
+    <string name="audio_room_unmute">Unmute</string>
     <string name="longs">Videos</string>
     <string name="articles">Articles</string>
     <string name="private_bookmarks">Private Bookmarks</string>

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip53LiveActivities/presence/MeetingRoomPresenceEvent.kt

@@ -31,8 +31,10 @@ import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
 import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
 import com.vitorpamplona.quartz.nip31Alts.alt
 import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingRoomEvent
+import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingSpaceEvent
 import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.tags.MeetingSpaceTag
 import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.HandRaisedTag
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.MutedTag
 import com.vitorpamplona.quartz.utils.TimeUtils
 
 @Immutable
@@ -53,6 +55,8 @@ class MeetingRoomPresenceEvent(
 
     fun handRaised() = tags.firstNotNullOfOrNull(HandRaisedTag::parse)
 
+    fun muted() = tags.firstNotNullOfOrNull(MutedTag::parse)
+
     companion object Companion {
         const val KIND = 10312
         const val ALT = "Room Presence tag"
@@ -78,5 +82,27 @@ class MeetingRoomPresenceEvent(
             }
             initializer()
         }
+
+        /**
+         * Convenience builder when the parent is a kind 30312 [MeetingSpaceEvent]
+         * (Clubhouse-style audio room). Mirrors the [MeetingRoomEvent] overload so
+         * a participant can publish presence + hand-raise + mute against an audio
+         * room without adapting to the meeting-room (kind 30313) variant.
+         */
+        fun build(
+            root: MeetingSpaceEvent,
+            handRaised: Boolean? = null,
+            muted: Boolean? = null,
+            createdAt: Long = TimeUtils.now(),
+            initializer: TagArrayBuilder<MeetingRoomPresenceEvent>.() -> Unit = {},
+        ) = eventTemplate(KIND, "", createdAt) {
+            alt(root.room() ?: ALT)
+
+            roomMeeting(MeetingSpaceTag(root.address(), root.relays().firstOrNull()))
+
+            handRaised?.let { handRaised(it) }
+            muted?.let { muted(it) }
+            initializer()
+        }
     }
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip53LiveActivities/presence/TagArrayBuilderExt.kt

@@ -26,9 +26,12 @@ import com.vitorpamplona.quartz.nip01Core.tags.aTag.toATag
 import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingRoomEvent
 import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.tags.MeetingSpaceTag
 import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.HandRaisedTag
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.MutedTag
 
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.roomMeeting(rep: MeetingSpaceTag) = addUnique(rep.toTagArray())
 
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.roomMeeting(rep: EventHintBundle<MeetingRoomEvent>) = addUnique(rep.toATag().toATagArray())
 
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.handRaised(raised: Boolean) = addUnique(HandRaisedTag.assemble(raised))
+
+fun TagArrayBuilder<MeetingRoomPresenceEvent>.muted(muted: Boolean) = addUnique(MutedTag.assemble(muted))

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip53LiveActivities/presence/tags/MutedTag.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip53LiveActivities.presence.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/**
+ * Mute flag for kind 10312 presence events used by Clubhouse-style audio
+ * rooms (e.g. nostrnests/nests). Carried alongside the optional `hand` tag so
+ * other clients can render the speaker as muted without waiting for the audio
+ * transport to drop frames.
+ */
+class MutedTag {
+    companion object Companion {
+        const val TAG_NAME = "muted"
+
+        fun parse(tag: Array<String>): Boolean? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1] == "1"
+        }
+
+        fun assemble(muted: Boolean) = arrayOf(TAG_NAME, if (muted) "1" else "0")
+    }
+}