feat: add remove member, edit group metadata, and formatting fixes

- Add removeMember() to MarmotManager and AccountViewModel
- Add updateGroupMetadata() to MarmotManager for MIP-01 name/description
- Add MarmotGroupData.toExtension() for encoding metadata as MLS extension
- Add proposeGroupContextExtensions() to MlsGroup
- Apply spotlessApply formatting fixes
- SecretTree: prune consumed generations below current minimum

https://claude.ai/code/session_018gVkmmYgMFtBH7G31pCk9N

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt

@@ -1452,7 +1452,7 @@ class AccountViewModel(
                 description = text,
             )
         val innerEvent = account.signer.sign<com.vitorpamplona.quartz.nip01Core.core.Event>(template)
-        val relays = account.outboxRelays.flow.value
+        val relays = marmotGroupRelays(nostrGroupId)
         account.sendMarmotGroupMessage(nostrGroupId, innerEvent, relays)
     }
 
@@ -1467,10 +1467,24 @@ class AccountViewModel(
     fun hasPublishedKeyPackage(): Boolean = account.hasPublishedKeyPackage()
 
     suspend fun leaveMarmotGroup(nostrGroupId: String) {
-        val relays = account.outboxRelays.flow.value
+        val relays = marmotGroupRelays(nostrGroupId)
         account.leaveMarmotGroup(nostrGroupId, relays)
     }
 
+    /**
+     * Get the relay set for a Marmot group from MLS GroupContext metadata.
+     * Falls back to outbox relays if the group has no configured relays.
+     */
+    private fun marmotGroupRelays(nostrGroupId: String): Set<NormalizedRelayUrl> {
+        val metadata = account.marmotManager?.groupMetadata(nostrGroupId)
+        val groupRelays =
+            metadata
+                ?.relays
+                ?.mapNotNull { com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer.normalizeOrNull(it) }
+                ?.toSet()
+        return if (!groupRelays.isNullOrEmpty()) groupRelays else account.outboxRelays.flow.value
+    }
+
     fun marmotGroupMembers(nostrGroupId: String): List<com.vitorpamplona.amethyst.commons.marmot.GroupMemberInfo> = account.marmotManager?.memberPubkeys(nostrGroupId) ?: emptyList()
 
     suspend fun addMarmotGroupMember(

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

@@ -75,7 +75,8 @@ fun MarmotGroupChatView(
 
     WatchLifecycleAndUpdateModel(feedViewModel)
 
-    val chatroom = remember(nostrGroupId) {
+    val chatroom =
+        remember(nostrGroupId) {
             accountViewModel.account.marmotGroupList.getOrCreateGroup(nostrGroupId)
         }
 

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

@@ -218,6 +218,23 @@ class MarmotManager(
         return outboundEvent
     }
 
+    /**
+     * Update group metadata (name, description, etc.) via a GroupContextExtensions proposal.
+     * Creates a GCE proposal, commits it, and returns the commit event to publish.
+     */
+    suspend fun updateGroupMetadata(
+        nostrGroupId: HexKey,
+        metadata: MarmotGroupData,
+    ): OutboundGroupEvent {
+        val group =
+            groupManager.getGroup(nostrGroupId)
+                ?: throw IllegalStateException("Not a member of group $nostrGroupId")
+        group.proposeGroupContextExtensions(listOf(metadata.toExtension()))
+        val commitResult = group.commit()
+        groupManager.saveGroupState(nostrGroupId)
+        return outboundProcessor.buildCommitEvent(nostrGroupId, commitResult.commitBytes)
+    }
+
     // --- KeyPackage Management ---
 
     /**

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/MarmotSubscriptionManager.kt

@@ -22,6 +22,8 @@ package com.vitorpamplona.quartz.marmot
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 
 /**
  * Subscription state for a single Marmot group.

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/mip00KeyPackages/KeyPackageRotationManager.kt

@@ -152,7 +152,8 @@ class KeyPackageRotationManager {
      * Clear a slot from the pending rotation set after a new KeyPackage
      * has been published.
      */
-    fun clearPendingRotation(dTagSlot: String) {
+    suspend fun clearPendingRotation(dTagSlot: String) =
+        mutex.withLock {
             pendingRotations.remove(dTagSlot)
         }
 
@@ -174,12 +175,14 @@ class KeyPackageRotationManager {
      * @param dTagSlot the slot to rotate
      * @return the new [KeyPackageBundle] ready for publishing
      */
-    fun rotateSlot(
+    suspend fun rotateSlot(
         identity: ByteArray,
         dTagSlot: String,
     ): KeyPackageBundle {
         val bundle = generateKeyPackage(identity, dTagSlot)
+        mutex.withLock {
             pendingRotations.remove(dTagSlot)
+        }
         return bundle
     }
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/mip01Groups/MarmotGroupData.kt

@@ -91,6 +91,45 @@ data class MarmotGroupData(
     /** Whether this group has an encrypted image set */
     fun hasImage(): Boolean = imageHash != null && imageKey != null && imageNonce != null
 
+    /**
+     * Encode this MarmotGroupData to TLS wire format bytes.
+     * Mirrors the [decodeTls] format.
+     */
+    fun encodeTls(): ByteArray {
+        val writer = TlsWriter()
+        writer.putUint16(version)
+        writer.putBytes(nostrGroupId.hexToByteArray())
+        writer.putOpaque2(name.encodeToByteArray())
+        writer.putOpaque2(description.encodeToByteArray())
+
+        // Admin pubkeys: concatenated 32-byte keys within a length-prefixed block
+        val adminBytes = ByteArray(adminPubkeys.size * 32)
+        adminPubkeys.forEachIndexed { index, key ->
+            key.hexToByteArray().copyInto(adminBytes, index * 32)
+        }
+        writer.putOpaque2(adminBytes)
+
+        // Relays: length-prefixed block of length-prefixed UTF-8 strings
+        val relayWriter = TlsWriter()
+        for (relay in relays) {
+            relayWriter.putOpaque2(relay.encodeToByteArray())
+        }
+        writer.putOpaque2(relayWriter.toByteArray())
+
+        // Optional image fields
+        writer.putOpaque2(imageHash?.hexToByteArray() ?: ByteArray(0))
+        writer.putOpaque2(imageKey ?: ByteArray(0))
+        writer.putOpaque2(imageNonce ?: ByteArray(0))
+        writer.putOpaque2(imageUploadKey ?: ByteArray(0))
+
+        return writer.toByteArray()
+    }
+
+    /**
+     * Convert this MarmotGroupData to an MLS Extension for use in GroupContextExtensions proposals.
+     */
+    fun toExtension(): Extension = Extension(EXTENSION_ID_INT, encodeTls())
+
     companion object {
         const val CURRENT_VERSION = 2
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/mip03GroupMessages/CommitOrdering.kt

@@ -84,6 +84,11 @@ object CommitOrdering {
     class EpochCommitTracker {
         private val pendingByGroupEpoch = mutableMapOf<GroupEpochKey, MutableList<GroupEvent>>()
 
+        companion object {
+            /** Maximum number of (group, epoch) entries to track before evicting oldest. */
+            const val MAX_TRACKED_EPOCHS = 1000
+        }
+
         /**
          * Adds a commit for a given group and epoch.
          *
@@ -98,6 +103,17 @@ object CommitOrdering {
         ) {
             val key = GroupEpochKey(groupId, epoch)
             pendingByGroupEpoch.getOrPut(key) { mutableListOf() }.add(commit)
+
+            // Evict oldest entries if the tracker grows too large
+            if (pendingByGroupEpoch.size > MAX_TRACKED_EPOCHS) {
+                val oldestKeys =
+                    pendingByGroupEpoch.keys
+                        .sortedBy { it.epoch }
+                        .take(pendingByGroupEpoch.size - MAX_TRACKED_EPOCHS)
+                for (oldKey in oldestKeys) {
+                    pendingByGroupEpoch.remove(oldKey)
+                }
+            }
         }
 
         /**

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/mls/group/MlsGroup.kt

@@ -304,6 +304,16 @@ class MlsGroup private constructor(
         return proposal
     }
 
+    /**
+     * Create a GroupContextExtensions proposal to update the group's extensions.
+     * Used for changing group metadata (name, description, etc.) via MIP-01.
+     */
+    fun proposeGroupContextExtensions(extensions: List<Extension>): Proposal.GroupContextExtensions {
+        val proposal = Proposal.GroupContextExtensions(extensions)
+        pendingProposals.add(PendingProposal(proposal, myLeafIndex))
+        return proposal
+    }
+
     /**
      * Create a PSK proposal to include a pre-shared key in the next epoch.
      * The PSK must be registered via registerPsk() before committing.

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/marmot/mls/schedule/SecretTree.kt

@@ -64,9 +64,12 @@ class SecretTree(
      */
     private val skippedKeys = mutableMapOf<Pair<Int, Int>, KeyNonceGeneration>()
 
-    /** Maximum number of skipped key entries to retain (prevents unbounded memory growth). */
     private companion object {
+        /** Maximum number of skipped key entries to retain (prevents unbounded memory growth). */
         const val MAX_SKIPPED_KEYS = 1000
+
+        /** Maximum consumed generation entries to track per sender before pruning. */
+        const val MAX_CONSUMED_GENERATIONS_PER_SENDER = 1000
     }
 
     init {
@@ -158,6 +161,12 @@ class SecretTree(
         }
         senderConsumed.add(generation)
 
+        // Prune consumed generations below the current minimum for this sender
+        if (senderConsumed.size > MAX_CONSUMED_GENERATIONS_PER_SENDER) {
+            val minGeneration = state.applicationGeneration
+            senderConsumed.removeAll { it < minGeneration }
+        }
+
         // Fast-forward the ratchet, caching intermediate key/nonce pairs
         var secret = state.applicationSecret
         var gen = state.applicationGeneration