fix(buzz): refresh the roster after a role change, and clear unread on open

**The roster went stale.** Promoting somebody changed nothing on screen until the
next cold start. Buzz signs its 39000-39003 with `d`/`p` tags and **no `h`**, yet
stores and fans them out channel-scoped — so a filter carrying `#h` does not match
their tags, and one without `#h` is a global subscription, which by design receives
no channel-scoped event. Neither shape can be live; measured it directly, a role
change delivers only the kind-40099 that narrates it.

So use that as the cue: the members screen re-reads the group's state whenever a
new system message lands in it, keyed on the message id so it fires once per
change rather than polling. Account.refreshRelayGroupState does the fetch.

**Unread badges never cleared.** loadAndMarkAsRead lived inside NormalChatNote —
the `else` of the render switch — so a row drawn by any specialised path (Buzz
system lines and activity rows, diffs, forum votes, NIP-28 admin lines, zaps)
never advanced the room's last-read marker. On a Buzz relay that is most rows:
joins, adds and role changes are all system messages, so a channel whose newest
events were those kept its badge no matter how often it was opened. Hoisted the
call to cover every row type; NormalChatNote's now-dead routeForLastRead
parameter is gone.

Verified on emulator-5554 against nosfabrica.communities.buzz.xyz: promoting a
member now shows the `admin` badge without restarting the app, and opening
`general` cleared its badge while the channels left untouched kept theirs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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

@@ -160,6 +160,7 @@ import com.vitorpamplona.amethyst.service.relayClient.reqCommand.nwc.NWCPaymentF
 import com.vitorpamplona.amethyst.service.uploads.FileHeader
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.EventProcessor
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.concordChannelLastReadRoute
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.relayGroup.datasource.RELAY_GROUP_METADATA_KINDS
 import com.vitorpamplona.quartz.buzz.dm.DmAddMemberEvent
 import com.vitorpamplona.quartz.buzz.dm.DmHideEvent
 import com.vitorpamplona.quartz.buzz.dm.DmOpenEvent
@@ -3422,6 +3423,26 @@ class Account(
         signAndSendPrivatelyOrBroadcast(template) { channel.relays().toList() }
     }
 
+    /**
+     * Re-reads a relay group's own state (39000-39003) from its host relay.
+     *
+     * Needed because Buzz never streams those. It signs them with `d`/`p` tags and **no `h`**, yet
+     * stores and fans them out channel-scoped — so a filter carrying `#h` does not match their tags,
+     * and one without `#h` is a global subscription, which by design receives no channel-scoped
+     * event. Neither shape can be live, so a role change or rename left the roster stale until the
+     * next cold start. What the relay does push is the kind-40099 that narrates the change; callers
+     * use that as the cue to call this.
+     */
+    suspend fun refreshRelayGroupState(channel: RelayGroupChannel) {
+        val relay = channel.groupId.relayUrl
+        val filter =
+            Filter(
+                kinds = RELAY_GROUP_METADATA_KINDS,
+                tags = mapOf("d" to listOf(channel.groupId.id)),
+            )
+        client.fetchAll(filters = mapOf(relay to listOf(filter)), timeoutMs = 8_000)
+    }
+
     /**
      * Add [pubkey] to the group (or change its roles) with a kind 9000 put-user
      * event (moderator only). Pass an empty [roles] list for a plain member.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/feed/ChatMessageCompose.kt

@@ -138,6 +138,18 @@ fun ChatroomMessageCompose(
             accountViewModel = accountViewModel,
             nav = nav,
         ) { canPreview ->
+            // Advance the room's last-read marker for whatever this row turns out to be. This used
+            // to live inside NormalChatNote — the `else` of the branch below — so a row rendered by
+            // any of the specialised paths (Buzz system lines and activity rows, diffs, forum votes,
+            // NIP-28 admin lines, zaps) never marked itself read. A channel whose newest events are
+            // system messages therefore kept its unread badge no matter how often it was opened,
+            // which on a Buzz relay is most channels: joins and role changes are system messages.
+            if (routeForLastRead != null) {
+                LaunchedEffect(key1 = routeForLastRead, key2 = baseNote.idHex) {
+                    accountViewModel.loadAndMarkAsRead(routeForLastRead, baseNote.createdAt(), dismissNotificationId = baseNote.idHex)
+                }
+            }
+
             val event = baseNote.event
             if (event is LnZapEvent) {
                 RenderChatZap(baseNote, accountViewModel, nav)
@@ -163,7 +175,6 @@ fun ChatroomMessageCompose(
             } else {
                 NormalChatNote(
                     baseNote,
-                    routeForLastRead,
                     innerQuote,
                     canPreview,
                     parentBackgroundColor,
@@ -194,7 +205,6 @@ fun ChatroomMessageCompose(
 @Composable
 fun NormalChatNote(
     note: Note,
-    routeForLastRead: String?,
     innerQuote: Boolean = false,
     canPreview: Boolean = true,
     parentBackgroundColor: MutableState<Color>? = null,
@@ -222,12 +232,6 @@ fun NormalChatNote(
             }
         }
 
-    if (routeForLastRead != null) {
-        LaunchedEffect(key1 = routeForLastRead) {
-            accountViewModel.loadAndMarkAsRead(routeForLastRead, note.createdAt(), dismissNotificationId = note.idHex)
-        }
-    }
-
     // A geohash chat asks own messages to still show the author line (which identity posted), so the
     // usual "hide the name on my own bubbles" shortcut is opt-out there.
     val showSelfAuthorName = LocalChatShowSelfAuthorName.current

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/RelayGroupMembersScreen.kt

@@ -86,13 +86,16 @@ import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.amethyst.ui.theme.Size35dp
 import com.vitorpamplona.amethyst.ui.theme.SuggestionListDefaultHeightChat
 import com.vitorpamplona.quartz.buzz.aoObserver.ObserverFrameEvent
+import com.vitorpamplona.quartz.buzz.stream.SystemMessageEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.relay.client.reqs.subscribeAsFlow
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
 import com.vitorpamplona.quartz.utils.TimeUtils
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.withContext
 
 /**
  * The roster of a NIP-29 group: everyone the relay lists as an admin (kind 39001)
@@ -116,6 +119,37 @@ fun RelayGroupMembersScreen(
     }
 }
 
+/**
+ * Re-reads a group's 39000-39003 whenever a new relay system message (kind 40099) lands in it.
+ *
+ * Keyed on the newest system message's id, so it fires once per change rather than polling, and not
+ * at all on a relay that doesn't emit them.
+ */
+@Composable
+private fun RefreshRelayGroupStateOnSystemMessage(
+    channel: RelayGroupChannel,
+    accountViewModel: AccountViewModel,
+) {
+    val notesState by channel
+        .flow()
+        .notes.stateFlow
+        .collectAsStateWithLifecycle()
+
+    val newestSystemMessageId =
+        remember(notesState) {
+            channel.notes
+                .filter { _, note -> note.event is SystemMessageEvent }
+                .maxByOrNull { it.createdAt() ?: 0L }
+                ?.idHex
+        }
+
+    LaunchedEffect(newestSystemMessageId) {
+        if (newestSystemMessageId != null) {
+            withContext(Dispatchers.IO) { accountViewModel.account.refreshRelayGroupState(channel) }
+        }
+    }
+}
+
 private class RosterEntry(
     val pubkey: HexKey,
     val membership: RelayGroupMembership,
@@ -141,6 +175,13 @@ private fun RelayGroupMembers(
     val channelState by observeChannel(baseChannel, accountViewModel)
     val channel = channelState?.channel as? RelayGroupChannel ?: baseChannel
 
+    // Buzz never streams the roster: it signs 39001/39002 with `d`/`p` and no `h`, yet stores and
+    // fans them channel-scoped — so a filter with `#h` doesn't match their tags and one without is a
+    // global subscription, which receives no channel-scoped event. Adding or promoting somebody
+    // therefore left this screen showing the old roles until the next cold start. The relay *does*
+    // push the kind-40099 narrating the change, so treat that as the cue to re-read the state.
+    RefreshRelayGroupStateOnSystemMessage(channel, accountViewModel)
+
     val myPubkey = accountViewModel.userProfile().pubkeyHex
     val iCanModerate = channel.membershipOf(myPubkey).canModerate()
     val iAmAdmin = channel.membershipOf(myPubkey) == RelayGroupMembership.ADMIN