feat(quartz): augment kind-10312 presence with publishing + onstage

Adds two NIP-53 presence tags used by nostrnests' room UI:

  ["publishing", "0|1"] — peer is actively pushing audio packets
  ["onstage",    "0|1"] — peer holds a speaker slot vs audience

These complement the existing "hand" and "muted" tags. They're
independent: a speaker can be onstage but paused (onstage=1,
publishing=0), or broadcasting silently (onstage=1, publishing=1,
muted=1). The participant grid (Tier 2) and listener counter (Tier 1
#8) consume them.

  - PublishingTag / OnstageTag classes mirror HandRaisedTag's parse +
    assemble shape exactly so the DSL (TagArrayBuilderExt) extends
    uniformly.
  - MeetingRoomPresenceEvent.publishing() / onstage() accessor parsers
    return Boolean? (null when the tag isn't present) so callers can
    distinguish "explicitly false" from "absent".
  - The MeetingSpaceEvent overload of build() now accepts both fields
    as nullable params; the MeetingRoomEvent overload deliberately
    doesn't (those are tier-2 video meetings, not Clubhouse rooms).
  - Round-trip tests pin the wire format and the "absent → null"
    behaviour.

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

@@ -35,6 +35,8 @@ import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingSpaceEv
 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.nip53LiveActivities.presence.tags.OnstageTag
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.PublishingTag
 import com.vitorpamplona.quartz.utils.TimeUtils
 
 @Immutable
@@ -57,6 +59,12 @@ class MeetingRoomPresenceEvent(
 
     fun muted() = tags.firstNotNullOfOrNull(MutedTag::parse)
 
+    /** True when the peer is actively pushing audio packets to the relay. */
+    fun publishing() = tags.firstNotNullOfOrNull(PublishingTag::parse)
+
+    /** True when the peer holds a speaker slot (vs. pure audience). */
+    fun onstage() = tags.firstNotNullOfOrNull(OnstageTag::parse)
+
     companion object Companion {
         const val KIND = 10312
         const val ALT = "Room Presence tag"
@@ -93,6 +101,8 @@ class MeetingRoomPresenceEvent(
             root: MeetingSpaceEvent,
             handRaised: Boolean? = null,
             muted: Boolean? = null,
+            publishing: Boolean? = null,
+            onstage: Boolean? = null,
             createdAt: Long = TimeUtils.now(),
             initializer: TagArrayBuilder<MeetingRoomPresenceEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, "", createdAt) {
@@ -102,6 +112,8 @@ class MeetingRoomPresenceEvent(
 
             handRaised?.let { handRaised(it) }
             muted?.let { muted(it) }
+            publishing?.let { publishing(it) }
+            onstage?.let { onstage(it) }
             initializer()
         }
     }

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

@@ -27,6 +27,8 @@ import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingRoomEve
 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.nip53LiveActivities.presence.tags.OnstageTag
+import com.vitorpamplona.quartz.nip53LiveActivities.presence.tags.PublishingTag
 
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.roomMeeting(rep: MeetingSpaceTag) = addUnique(rep.toTagArray())
 
@@ -35,3 +37,7 @@ fun TagArrayBuilder<MeetingRoomPresenceEvent>.roomMeeting(rep: EventHintBundle<M
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.handRaised(raised: Boolean) = addUnique(HandRaisedTag.assemble(raised))
 
 fun TagArrayBuilder<MeetingRoomPresenceEvent>.muted(muted: Boolean) = addUnique(MutedTag.assemble(muted))
+
+fun TagArrayBuilder<MeetingRoomPresenceEvent>.publishing(publishing: Boolean) = addUnique(PublishingTag.assemble(publishing))
+
+fun TagArrayBuilder<MeetingRoomPresenceEvent>.onstage(onstage: Boolean) = addUnique(OnstageTag.assemble(onstage))

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

@@ -0,0 +1,52 @@
+/*
+ * 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
+
+/**
+ * `["onstage", "0|1"]` on a kind-10312 presence event.
+ *
+ * Distinguishes a "speaker slot holder" (`onstage=1`) from a pure
+ * audience member (`onstage=0`). The participant grid (Tier 2)
+ * places onstage peers in the top section and audience members in
+ * the audience section; the listener counter (#8) counts the
+ * complement.
+ *
+ * Independent of [PublishingTag]: a speaker can be onstage but
+ * paused (onstage=1, publishing=0), or broadcasting silently
+ * (onstage=1, publishing=1, muted=1).
+ */
+class OnstageTag {
+    companion object Companion {
+        const val TAG_NAME = "onstage"
+
+        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(onstage: Boolean) = arrayOf(TAG_NAME, if (onstage) "1" else "0")
+    }
+}

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

@@ -0,0 +1,52 @@
+/*
+ * 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
+
+/**
+ * `["publishing", "0|1"]` on a kind-10312 presence event.
+ *
+ * Indicates whether this peer is currently pushing audio to the
+ * relay (i.e. holds an active speaker slot AND is not muted nor
+ * paused). Distinct from [MutedTag], which can be true while still
+ * publishing silence; `publishing=1, muted=1` is "I'm a speaker but
+ * temporarily muted", and `publishing=0` means no audio packets at
+ * all.
+ *
+ * The participant grid (Tier 2) uses this to render an "active
+ * waveform" indicator only on peers actually broadcasting.
+ */
+class PublishingTag {
+    companion object Companion {
+        const val TAG_NAME = "publishing"
+
+        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(publishing: Boolean) = arrayOf(TAG_NAME, if (publishing) "1" else "0")
+    }
+}

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip53LiveActivities/presence/MeetingRoomPresenceEventTest.kt

@@ -49,6 +49,45 @@ class MeetingRoomPresenceEventTest {
         assertEquals("${MeetingRoomPresenceEvent.KIND}:$participant:", event.addressTag())
     }
 
+    @Test
+    fun parsesPublishingAndOnstageTags() {
+        val event =
+            MeetingRoomPresenceEvent(
+                id = "0".repeat(64),
+                pubKey = participant,
+                createdAt = 1_700_000_000L,
+                tags =
+                    arrayOf(
+                        arrayOf("a", "30312:${"b".repeat(64)}:room"),
+                        arrayOf("hand", "0"),
+                        arrayOf("muted", "1"),
+                        arrayOf("publishing", "1"),
+                        arrayOf("onstage", "1"),
+                    ),
+                content = "",
+                sig = "0".repeat(128),
+            )
+        assertEquals(false, event.handRaised())
+        assertEquals(true, event.muted())
+        assertEquals(true, event.publishing())
+        assertEquals(true, event.onstage())
+    }
+
+    @Test
+    fun missingPublishingAndOnstageTagsReturnNull() {
+        val event =
+            MeetingRoomPresenceEvent(
+                id = "0".repeat(64),
+                pubKey = participant,
+                createdAt = 1_700_000_000L,
+                tags = arrayOf(arrayOf("a", "30312:${"b".repeat(64)}:room")),
+                content = "",
+                sig = "0".repeat(128),
+            )
+        assertEquals(null, event.publishing())
+        assertEquals(null, event.onstage())
+    }
+
     @Test
     fun createAddressKeysByPubKeyOnly() {
         val a = MeetingRoomPresenceEvent.createAddress(participant)