refactor: make Marmot group members list reactive

Expose the member list as MutableStateFlow<List<GroupMemberInfo>> on
MarmotGroupChatroom, populated by MarmotManager.syncMetadataTo alongside
the existing memberCount. MarmotGroupInfoScreen and RemoveMemberScreen
now observe it via collectAsStateWithLifecycle, so both remote commits
(already routed through syncMetadataTo in DecryptAndIndexProcessor) and
local mutations refresh the UI without manual re-queries.

Account.addMarmotGroupMember and removeMarmotGroupMember now call
syncMetadataTo right after the MLS state is mutated, mirroring the
pattern already used by updateMarmotGroupMetadata, so the local change
is visible immediately without waiting for the relay round-trip.

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

@@ -2070,6 +2070,13 @@ class Account(
                 relays = groupRelays,
             )
 
+        // The MLS commit has already been applied to the local group state —
+        // surface the new member list in the chatroom now so observers (e.g.
+        // MarmotGroupInfoScreen) update without waiting for our own commit to
+        // loop back through the relay.
+        val chatroom = marmotGroupList.getOrCreateGroup(nostrGroupId)
+        manager.syncMetadataTo(nostrGroupId, chatroom)
+
         Log.d("MarmotDbg") {
             "addMarmotGroupMember: built commit kind=${commitEvent.signedEvent.kind} id=${commitEvent.signedEvent.id.take(8)}… " +
                 "welcomeDelivery=${if (welcomeDelivery != null) "present(giftWrapId=${welcomeDelivery.giftWrapEvent.id.take(8)}…)" else "null"}"
@@ -2270,6 +2277,8 @@ class Account(
         if (!isWriteable()) return
 
         val outbound = manager.removeMember(nostrGroupId, targetLeafIndex)
+        val chatroom = marmotGroupList.getOrCreateGroup(nostrGroupId)
+        manager.syncMetadataTo(nostrGroupId, chatroom)
         client.publish(outbound.signedEvent, groupRelays)
     }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/marmotGroup/MarmotGroupInfoScreen.kt

@@ -58,7 +58,6 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
-import androidx.lifecycle.compose.LifecycleResumeEffect
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.commons.marmot.GroupMemberInfo
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
@@ -85,19 +84,13 @@ fun MarmotGroupInfoScreen(
     val groupDescription by chatroom.description.collectAsStateWithLifecycle()
     val adminPubkeys by chatroom.adminPubkeys.collectAsStateWithLifecycle()
     val groupRelays by chatroom.relays.collectAsStateWithLifecycle()
-    var members by remember { mutableStateOf(emptyList<GroupMemberInfo>()) }
+    val members by chatroom.members.collectAsStateWithLifecycle()
     var showLeaveDialog by remember { mutableStateOf(false) }
     var isLeaving by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
     val myPubkey = accountViewModel.account.signer.pubKey
     val context = LocalContext.current
 
-    LifecycleResumeEffect(nostrGroupId) {
-        members = accountViewModel.marmotGroupMembers(nostrGroupId)
-        chatroom.memberCount.value = members.size
-        onPauseOrDispose {}
-    }
-
     Scaffold(
         topBar = {
             TopAppBar(

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/marmotGroup/RemoveMemberScreen.kt

@@ -44,7 +44,6 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -55,6 +54,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.commons.marmot.GroupMemberInfo
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.note.UserPicture
@@ -71,17 +71,17 @@ fun RemoveMemberScreen(
     accountViewModel: AccountViewModel,
     nav: INav,
 ) {
-    var members by remember { mutableStateOf(emptyList<GroupMemberInfo>()) }
+    val chatroom =
+        remember(nostrGroupId) {
+            accountViewModel.account.marmotGroupList.getOrCreateGroup(nostrGroupId)
+        }
+    val members by chatroom.members.collectAsStateWithLifecycle()
     var memberToRemove by remember { mutableStateOf<GroupMemberInfo?>(null) }
     var isRemoving by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
     val myPubkey = accountViewModel.account.signer.pubKey
     val context = LocalContext.current
 
-    LaunchedEffect(nostrGroupId) {
-        members = accountViewModel.marmotGroupMembers(nostrGroupId)
-    }
-
     Scaffold(
         topBar = {
             TopAppBar(
@@ -155,7 +155,6 @@ fun RemoveMemberScreen(
                 scope.launch(Dispatchers.IO) {
                     try {
                         accountViewModel.removeMarmotGroupMember(nostrGroupId, member.leafIndex)
-                        members = accountViewModel.marmotGroupMembers(nostrGroupId)
                         isRemoving = false
                         launch(Dispatchers.Main) {
                             Toast

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/marmot/MarmotManager.kt

@@ -437,7 +437,9 @@ class MarmotManager(
             chatroom.adminPubkeys.value = metadata.adminPubkeys
             chatroom.relays.value = metadata.relays
         }
-        chatroom.memberCount.value = memberCount(nostrGroupId)
+        val members = memberPubkeys(nostrGroupId)
+        chatroom.members.value = members
+        chatroom.memberCount.value = members.size
     }
 }
 

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/marmotGroups/MarmotGroupChatroom.kt

@@ -21,6 +21,7 @@
 package com.vitorpamplona.amethyst.commons.model.marmotGroups
 
 import androidx.compose.runtime.Stable
+import com.vitorpamplona.amethyst.commons.marmot.GroupMemberInfo
 import com.vitorpamplona.amethyst.commons.model.Channel.Companion.DefaultFeedOrder
 import com.vitorpamplona.amethyst.commons.model.ListChange
 import com.vitorpamplona.amethyst.commons.model.Note
@@ -46,6 +47,7 @@ class MarmotGroupChatroom(
     var adminPubkeys = MutableStateFlow<List<HexKey>>(emptyList())
     var relays = MutableStateFlow<List<String>>(emptyList())
     var memberCount = MutableStateFlow(0)
+    var members = MutableStateFlow<List<GroupMemberInfo>>(emptyList())
     var newestMessage: Note? = null
     val unreadCount = MutableStateFlow(0)