refactor(nests): keep room presence out of channel.notes entirely

Presence (kind-10312) was being stored in both `channel.notes` and the
`presenceNotes` index. The mixed-kind `notes` map is dominated by chat
in active rooms, and only HomeLiveFilter still read presence from it --
which is now migrated to scan presenceNotes directly.

- LocalCache.consume(MeetingRoomPresenceEvent): drop the `channel.addNote`
  call; only addPresenceNote, plus addRelay so the channel's relay-counter
  still tracks where presence arrived from.
- LiveActivitiesChannel: addPresenceNote / removePresenceNote emit on
  flowSet.notes so reactive observers (NestsFeedLoaded) still update.
- HomeLiveFilter.shouldIncludeChannel: scan presenceNotes separately for
  follow-broadcast detection in audio rooms (chat scan unchanged).
- HomeLiveFilter.followsThatParticipateOn: also count presenceNotes
  authors so audio-room hosts/speakers factor into the participation
  sort even when they haven't chatted.
- ChannelFeedFilter: delete the isChatEvent workaround that was excluding
  presence from the chat feed -- presence no longer lands there.

amethyst/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -1549,28 +1549,24 @@ object LocalCache : ILocalCache, ICacheProvider {
     }
 
     /**
-     * Audio-room presence (kind-10312) — addressable storage AND
-     * attach the version note to the room's [LiveActivitiesChannel].
-     * The home live-bubble surfaces a room when a follow is
-     * publishing in it; that fan-out walks `channel.notes`, so the
-     * presence event needs to be in there alongside chat. Without
-     * this, presence-driven inclusion can't see follows broadcasting
-     * in the room (only chat-driven inclusion would fire).
+     * Audio-room presence (kind-10312) — addressable storage plus an
+     * author-keyed entry in the room's
+     * [LiveActivitiesChannel.presenceNotes] index.
      *
-     * Also indexed under [LiveActivitiesChannel.presenceNotes] keyed
-     * by author so the Nests feed can answer "are there speakers on
-     * stage?" without scanning the chat-dominated `notes` map.
+     * Presence is intentionally NOT added to `channel.notes`: that
+     * map is dominated by chat in active rooms and feeds that care
+     * about presence (Nests drawer, home live-bubble, NestsFeedLoaded)
+     * iterate `presenceNotes` directly for an O(speakers) scan.
      *
      * Cross-room move handling: kind-10312 is replaceable per author,
      * but the room a presence points to (`a`-tag) can change when a
-     * speaker hops between rooms. The replaceable cache only swaps the
-     * addressable's content — it has no notion of which channel the
-     * old version was attached to. Without explicit eviction the old
-     * room would keep surfacing as "live" via the stale entry until it
-     * dropped out of the freshness window. Capture the prior room
-     * before replacement and, when it differs, drop the author from
-     * the old channel's presence index and the old version note from
-     * its main `notes` index.
+     * speaker hops between rooms. The replaceable cache only swaps
+     * the addressable's content — it has no notion of which channel
+     * the old version was attached to. Without explicit eviction the
+     * old room would keep surfacing as "live" via the stale entry
+     * until it dropped out of the freshness window. Capture the prior
+     * room before replacement and, when it differs, drop the author
+     * from the old channel's presence index.
      */
     fun consume(
         event: MeetingRoomPresenceEvent,
@@ -1583,24 +1579,17 @@ object LocalCache : ILocalCache, ICacheProvider {
 
         val new = consumeBaseReplaceable(event, relay, wasVerified)
 
-        // The replaceable cache keys this on the AUTHOR's address
-        // (kind=10312, pubkey, fixed-d-tag) — independent of the
-        // room. To wire the room bubble we also attach the version
-        // note to the room's channel keyed by its kind-30312 address.
         val roomAddress = event.interactiveRoom()?.address ?: return new
         if (roomAddress.kind != MeetingSpaceEvent.KIND) return new
 
         if (isReplacement && priorRoomAddress != null && priorRoomAddress != roomAddress) {
-            getLiveActivityChannelIfExists(priorRoomAddress)?.let { priorChannel ->
-                priorChannel.removePresenceNote(event.pubKey)
-                getNoteIfExists(priorVersion.id)?.let { priorChannel.removeNote(it) }
-            }
+            getLiveActivityChannelIfExists(priorRoomAddress)?.removePresenceNote(event.pubKey)
         }
 
         val channel = getOrCreateLiveChannel(roomAddress)
         val versionNote = getOrCreateNote(event.id)
-        channel.addNote(versionNote, relay)
         channel.addPresenceNote(versionNote)
+        if (relay != null) channel.addRelay(relay)
 
         return new
     }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/dal/ChannelFeedFilter.kt

@@ -26,7 +26,6 @@ import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.ui.dal.AdditiveFeedFilter
 import com.vitorpamplona.amethyst.ui.dal.ChangesFlowFilter
 import com.vitorpamplona.amethyst.ui.dal.DefaultFeedOrder
-import com.vitorpamplona.quartz.nip53LiveActivities.presence.MeetingRoomPresenceEvent
 
 class ChannelFeedFilter(
     val channel: Channel,
@@ -38,25 +37,12 @@ class ChannelFeedFilter(
     override fun changesFlow() = channel.changesFlow()
 
     // returns the last Note of each user.
-    override fun feed(): List<Note> = sort(channel.notes.filterIntoSet { _, it -> isChatEvent(it) && account.isAcceptable(it) })
+    override fun feed(): List<Note> = sort(channel.notes.filterIntoSet { _, it -> account.isAcceptable(it) })
 
     override fun applyFilter(newItems: Set<Note>): Set<Note> =
         newItems
-            .filter { channel.notes.containsKey(it.idHex) && isChatEvent(it) && account.isAcceptable(it) }
+            .filter { channel.notes.containsKey(it.idHex) && account.isAcceptable(it) }
             .toSet()
 
     override fun sort(items: Set<Note>): List<Note> = items.sortedWith(DefaultFeedOrder)
-
-    /**
-     * Reject non-chat events that get attached to a [Channel] for other
-     * surfaces. The current case: kind-10312
-     * [MeetingRoomPresenceEvent]s land in `channel.notes` so the home
-     * live-bubble can detect a follow broadcasting in a Nest
-     * (HomeLiveFilter scans channel.notes); they have no chat content
-     * and would otherwise render as an empty card in the chat panel.
-     *
-     * Anything else is passed through — chat messages, zaps, raids,
-     * clips, channel-create / metadata events all belong here.
-     */
-    private fun isChatEvent(note: Note): Boolean = note.event !is MeetingRoomPresenceEvent
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/dal/HomeLiveFilter.kt

@@ -103,6 +103,16 @@ class HomeLiveFilter(
             return true
         }
 
+        // Audio-room presence (kind-10312) lives in `presenceNotes`,
+        // not `notes`. Check it separately so a follow broadcasting in
+        // a Nest still surfaces the bubble even if no chat happened.
+        val hasPresence =
+            channel.presenceNotes
+                .filter { _, note ->
+                    acceptableChatEvent(note, filterParams, timeLimit)
+                }.isNotEmpty()
+        if (hasPresence) return true
+
         return channel.notes
             .filter { _, value ->
                 acceptableChatEvent(value, filterParams, timeLimit)
@@ -284,6 +294,18 @@ class HomeLiveFilter(
             }
         }
 
+        // Audio-room presence is indexed separately from `notes`. Add
+        // its author count so audio-room hosts/speakers still factor
+        // into the follow-participation sort even when they haven't
+        // chatted in the room.
+        if (channel is LiveActivitiesChannel) {
+            channel.presenceNotes.forEach { authorHex, _ ->
+                if (followingSet == null || authorHex in followingSet) {
+                    count++
+                }
+            }
+        }
+
         return count
     }
 }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/nip53LiveActivities/LiveActivitiesChannel.kt

@@ -49,15 +49,22 @@ class LiveActivitiesChannel(
      * unbounded the way `notes` does. Empty for streaming channels
      * (kind-30311) — only kind-30312 rooms publish presence.
      *
-     * Lets feeds answer "is anyone live on stage in this room?"
-     * without scanning the chat-dominated `notes` map. See
-     * [com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.dal.NestsFeedFilter].
+     * Presence lives ONLY here, not in the base `notes` map: the
+     * mixed-kind `notes` is dominated by chat in active rooms and
+     * iterating it just to find presence is wasteful. Feeds that need
+     * "is anyone live on stage in this room?" iterate this index
+     * directly. See
+     * [com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.dal.NestsFeedFilter]
+     * and [com.vitorpamplona.amethyst.ui.screen.loggedIn.home.dal.HomeLiveFilter].
      */
     val presenceNotes = LargeCache<HexKey, Note>()
 
     fun addPresenceNote(note: Note) {
         val author = note.author?.pubkeyHex ?: return
+        val previous = presenceNotes.get(author)
+        if (previous?.idHex == note.idHex) return
         presenceNotes.put(author, note)
+        flowSet?.notes?.invalidateData()
     }
 
     /**
@@ -68,7 +75,9 @@ class LiveActivitiesChannel(
      * freshness window.
      */
     fun removePresenceNote(author: HexKey) {
+        if (!presenceNotes.containsKey(author)) return
         presenceNotes.remove(author)
+        flowSet?.notes?.invalidateData()
     }
 
     fun address() = address