Merge remote-tracking branch 'origin/main' into codex/nostr-double-ratchet

app/src/main/java/com/bitchat/android/protocol/BinaryProtocol.kt

@@ -183,7 +183,6 @@ object BinaryProtocol {
     private const val SENDER_ID_SIZE = 8
     private const val RECIPIENT_ID_SIZE = 8
     private const val SIGNATURE_SIZE = 64
-
     object Flags {
         const val HAS_RECIPIENT: UByte = 0x01u
         const val HAS_SIGNATURE: UByte = 0x02u
@@ -200,6 +199,15 @@ object BinaryProtocol {
     
     fun encode(packet: BitchatPacket, padding: Boolean = true): ByteArray? {
         try {
+            val maxPayloadLength = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+            if (packet.payload.size > maxPayloadLength) {
+                Log.w(
+                    "BinaryProtocol",
+                    "Cannot encode payload ${packet.payload.size} above receiver limit $maxPayloadLength"
+                )
+                return null
+            }
+
             // Try to compress payload if beneficial
             var payload = packet.payload
             var originalPayloadSize: Int? = null
@@ -324,21 +332,36 @@ object BinaryProtocol {
         }
     }
     
-    fun decode(data: ByteArray): BitchatPacket? {
+    fun decode(data: ByteArray): BitchatPacket? =
+        decode(data, CompressionUtil::decompressWithResourcesReserved)
+
+    /** Test seam used to prove rejected expansion sizes never reach inflation. */
+    internal fun decodeForTesting(
+        data: ByteArray,
+        decompress: (ByteArray, Int) -> ByteArray?
+    ): BitchatPacket? = decode(data, decompress)
+
+    private fun decode(
+        data: ByteArray,
+        decompress: (ByteArray, Int) -> ByteArray?
+    ): BitchatPacket? {
         // Try decode as-is first (robust when padding wasn't applied) - iOS fix
-        decodeCore(data)?.let { return it }
+        decodeCore(data, decompress)?.let { return it }
         
         // If that fails, try after removing padding
         val unpadded = MessagePadding.unpad(data)
         if (unpadded.contentEquals(data)) return null // No padding was removed, already failed
         
-        return decodeCore(unpadded)
+        return decodeCore(unpadded, decompress)
     }
     
     /**
      * Core decoding implementation used by decode() with and without padding removal - iOS fix
      */
-    private fun decodeCore(raw: ByteArray): BitchatPacket? {
+    private fun decodeCore(
+        raw: ByteArray,
+        decompress: (ByteArray, Int) -> ByteArray?
+    ): BitchatPacket? {
         try {
             if (raw.size < HEADER_SIZE_V1 + SENDER_ID_SIZE) return null
 
@@ -435,23 +458,45 @@ object BinaryProtocol {
                 } else {
                     buffer.getShort().toUShort().toInt()
                 }
+
+                val maxExpandedSize = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+                if (originalSize <= 0 || originalSize > maxExpandedSize) {
+                    Log.w(
+                        "BinaryProtocol",
+                        "Expanded payload size $originalSize is outside the allowed range 1..$maxExpandedSize"
+                    )
+                    return null
+                }
                 
                 // Compressed payload
                 val compressedSize = payloadLength.toInt() - lengthFieldBytes
-                val compressedPayload = ByteArray(compressedSize)
-                buffer.get(compressedPayload)
-
+                if (compressedSize == 0) {
+                    Log.w("BinaryProtocol", "Compressed payload has no deflate bytes")
+                    return null
+                }
                 // Security check: Compression bomb protection
-                if (compressedSize > 0) {
-                    val ratio = originalSize.toDouble() / compressedSize.toDouble()
-                    if (ratio > 50_000.0) {
-                        Log.w("BinaryProtocol", "🚫 Suspicious compression ratio: ${ratio}:1")
-                        return null
-                    }
+                val ratio = originalSize.toDouble() / compressedSize.toDouble()
+                if (ratio > 50_000.0) {
+                    Log.w("BinaryProtocol", "🚫 Suspicious compression ratio: ${ratio}:1")
+                    return null
                 }
                 
-                // Decompress
-                CompressionUtil.decompress(compressedPayload, originalSize) ?: return null
+                // Reserve the compressed copy plus expanded output before either allocation.
+                // Small packets share the memory pool; packets wait only while its budget is full.
+                val resourceBytes = compressedSize.toLong() + originalSize.toLong()
+                val expandedPayload = CompressionUtil.withDecompressionResources(resourceBytes) {
+                    val compressedPayload = ByteArray(compressedSize)
+                    buffer.get(compressedPayload)
+                    decompress(compressedPayload, originalSize)
+                } ?: return null
+                if (expandedPayload.size != originalSize) {
+                    Log.w(
+                        "BinaryProtocol",
+                        "Expanded payload size ${expandedPayload.size} did not match declared size $originalSize"
+                    )
+                    return null
+                }
+                expandedPayload
             } else {
                 val payloadBytes = ByteArray(payloadLength.toInt())
                 buffer.get(payloadBytes)
@@ -477,7 +522,7 @@ object BinaryProtocol {
                 route = route
             )
             
-        } catch (e: Throwable) {
+        } catch (e: Exception) {
             Log.e("BinaryProtocol", "Error decoding packet: ${e.message}")
             return null
         }

app/src/main/java/com/bitchat/android/protocol/CompressionUtil.kt

@@ -2,6 +2,7 @@ package com.bitchat.android.protocol
 
 import android.util.Log
 import java.io.ByteArrayOutputStream
+import java.util.zip.DataFormatException
 import java.util.zip.Deflater
 import java.util.zip.Inflater
 
@@ -11,6 +12,8 @@ import java.util.zip.Inflater
  */
 object CompressionUtil {
     private const val COMPRESSION_THRESHOLD = com.bitchat.android.util.AppConstants.Protocol.COMPRESSION_THRESHOLD_BYTES  // bytes - same as iOS
+
+    private val decompressionPool = DecompressionResourcePool.forRuntime()
     
     /**
      * Helper to check if compression is worth it - exact same logic as iOS
@@ -73,47 +76,124 @@ object CompressionUtil {
      * iOS COMPRESSION_ZLIB produces raw deflate data (no headers)
      */
     fun decompress(compressedData: ByteArray, originalSize: Int): ByteArray? {
-        // iOS COMPRESSION_ZLIB produces raw deflate format (no headers)
-        try {
-            val inflater = Inflater(true) // true = raw deflate, no headers
-            inflater.setInput(compressedData)
-            
-            val decompressedBuffer = ByteArray(originalSize)
-            val actualSize = inflater.inflate(decompressedBuffer)
-            inflater.end()
-            
-            // Verify decompressed size matches expected (same validation as iOS)
-            return if (actualSize == originalSize) {
-                decompressedBuffer
-            } else if (actualSize > 0) {
-                // Handle case where actual size is different
-                decompressedBuffer.copyOfRange(0, actualSize)
-            } else {
+        if (!isValidRequest(compressedData, originalSize)) return null
+        return withDecompressionResources(originalSize.toLong()) {
+            decompressWithResourcesReserved(compressedData, originalSize)
+        }
+    }
+
+    internal fun <T> withDecompressionResources(bytes: Long, block: () -> T): T? =
+        decompressionPool.withReservation(bytes, block)
+
+    /**
+     * Inflate after the caller has reserved all packet-specific allocations.
+     * This avoids nested acquisition when BinaryProtocol reserves both its input copy and output.
+     */
+    internal fun decompressWithResourcesReserved(
+        compressedData: ByteArray,
+        originalSize: Int
+    ): ByteArray? {
+        if (!isValidRequest(compressedData, originalSize)) return null
+        return decompressExact(compressedData, originalSize)
+    }
+
+    private fun isValidRequest(compressedData: ByteArray, originalSize: Int): Boolean {
+        val maxExpandedSize = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+        if (compressedData.isEmpty()) {
+            Log.w("CompressionUtil", "Refusing an empty compressed payload")
+            return false
+        }
+        if (originalSize <= 0 || originalSize > maxExpandedSize) {
+            Log.w(
+                "CompressionUtil",
+                "Refusing expanded payload size $originalSize outside 1..$maxExpandedSize"
+            )
+            return false
+        }
+        return true
+    }
+
+    private fun decompressExact(compressedData: ByteArray, originalSize: Int): ByteArray? {
+        return if (looksLikeZlib(compressedData)) {
+            // A raw stream can coincidentally begin with a valid-looking zlib header. The
+            // header therefore only determines which format to try first; any non-exact zlib
+            // result must still fall back to raw under the same size/completion bounds.
+            val zlibResult = try {
+                inflateExact(compressedData, originalSize, nowrap = false)
+            } catch (zlibException: DataFormatException) {
                 null
             }
-        } catch (e: Exception) {
-            Log.d("CompressionUtil", "Raw deflate decompression failed: ${e.message}, trying with zlib headers...")
-            
-            // Fallback: try with zlib headers in case of mixed usage
-            try {
-                val inflater = Inflater(false) // false = expect zlib headers
-                inflater.setInput(compressedData)
-                
-                val decompressedBuffer = ByteArray(originalSize)
-                val actualSize = inflater.inflate(decompressedBuffer)
-                inflater.end()
-                
-                return if (actualSize == originalSize) {
-                    decompressedBuffer
-                } else if (actualSize > 0) {
-                    decompressedBuffer.copyOfRange(0, actualSize)
-                } else {
+            if (zlibResult != null) {
+                zlibResult
+            } else {
+                try {
+                    inflateExact(compressedData, originalSize, nowrap = true)
+                } catch (rawException: DataFormatException) {
+                    Log.d("CompressionUtil", "Invalid zlib/raw deflate stream")
                     null
                 }
-            } catch (fallbackException: Exception) {
-                Log.e("CompressionUtil", "Both raw deflate and zlib decompression failed: ${fallbackException.message}")
-                return null
             }
+        } else {
+            try {
+                inflateExact(compressedData, originalSize, nowrap = true)
+            } catch (rawException: DataFormatException) {
+                Log.d("CompressionUtil", "Invalid raw deflate stream")
+                null
+            }
+        }
+    }
+
+    /** RFC 1950 header check used to avoid speculative double inflation. */
+    private fun looksLikeZlib(data: ByteArray): Boolean {
+        if (data.size < 2) return false
+        val cmf = data[0].toInt() and 0xFF
+        val flg = data[1].toInt() and 0xFF
+        return (cmf and 0x0F) == 8 &&
+            (cmf ushr 4) <= 7 &&
+            ((cmf shl 8) or flg) % 31 == 0
+    }
+
+    /**
+     * Inflate one complete stream into exactly [originalSize] bytes.
+     *
+     * A full output buffer alone is not success: an attacker can under-declare a larger stream so
+     * the first inflate call fills the buffer while [Inflater.finished] remains false. Conversely,
+     * a truncated or over-declared stream can produce a non-empty prefix. Both forms are rejected,
+     * as are trailing bytes after the compressed stream.
+     *
+     * [DataFormatException] is deliberately allowed to escape so the caller can try the legacy
+     * zlib-wrapped format. Size/completion mismatches return null; the fallback must then prove the
+     * same bytes are a complete, exact-sized zlib stream before they can be accepted.
+     */
+    @Throws(DataFormatException::class)
+    private fun inflateExact(
+        compressedData: ByteArray,
+        originalSize: Int,
+        nowrap: Boolean
+    ): ByteArray? {
+        val inflater = Inflater(nowrap)
+        return try {
+            inflater.setInput(compressedData)
+            val output = ByteArray(originalSize)
+            var written = 0
+
+            while (written < originalSize) {
+                val count = inflater.inflate(output, written, originalSize - written)
+                if (count == 0) break
+                written += count
+            }
+
+            if (written != originalSize) return null
+
+            // Give Inflater one byte of room to consume the end marker. Any produced byte proves
+            // the declared size was smaller than the actual expansion.
+            val overflowProbe = ByteArray(1)
+            if (inflater.inflate(overflowProbe) != 0) return null
+
+            if (!inflater.finished() || inflater.remaining != 0) return null
+            output
+        } finally {
+            inflater.end()
         }
     }
     

app/src/main/java/com/bitchat/android/protocol/DecompressionResourcePool.kt

@@ -0,0 +1,73 @@
+package com.bitchat.android.protocol
+
+import java.util.concurrent.Semaphore
+import java.util.concurrent.TimeUnit
+import kotlin.math.ceil
+
+/**
+ * Fair, weighted admission control for decompression allocations.
+ *
+ * Permits represent memory rather than workers: small packets can proceed concurrently while
+ * near-limit packets consume most of the budget. Callers must reserve before allocating any
+ * packet-specific compressed copy or expanded output.
+ */
+internal class DecompressionResourcePool(
+    budgetBytes: Long,
+    private val unitBytes: Int,
+    private val waitTimeoutMs: Long
+) {
+    private val totalPermits = (budgetBytes / unitBytes).toInt().coerceAtLeast(1)
+    private val permits = Semaphore(totalPermits, true)
+
+    fun <T> withReservation(bytes: Long, block: () -> T): T? {
+        val requiredPermits = permitsFor(bytes)
+        val acquired = try {
+            permits.tryAcquire(requiredPermits, waitTimeoutMs, TimeUnit.MILLISECONDS)
+        } catch (_: InterruptedException) {
+            Thread.currentThread().interrupt()
+            false
+        }
+        if (!acquired) return null
+
+        return try {
+            block()
+        } finally {
+            permits.release(requiredPermits)
+        }
+    }
+
+    internal fun permitsFor(bytes: Long): Int =
+        ceil(bytes.coerceAtLeast(1).toDouble() / unitBytes.toDouble())
+            .toInt()
+            .coerceAtMost(totalPermits)
+
+    internal val availablePermits: Int
+        get() = permits.availablePermits()
+
+    companion object {
+        private const val DEFAULT_UNIT_BYTES = 256 * 1024
+        private const val DEFAULT_WAIT_TIMEOUT_MS = 1_000L
+        private const val HEAP_BUDGET_DIVISOR = 8L
+        private const val MAX_BUDGET_BYTES = 64L * 1024 * 1024
+
+        fun forRuntime(
+            maxHeapBytes: Long = Runtime.getRuntime().maxMemory(),
+            maxPacketResourceBytes: Long =
+                2L * com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+        ): DecompressionResourcePool {
+            val budget = recommendedBudgetBytes(maxHeapBytes, maxPacketResourceBytes)
+            return DecompressionResourcePool(
+                budgetBytes = budget,
+                unitBytes = DEFAULT_UNIT_BYTES,
+                waitTimeoutMs = DEFAULT_WAIT_TIMEOUT_MS
+            )
+        }
+
+        internal fun recommendedBudgetBytes(
+            maxHeapBytes: Long,
+            maxPacketResourceBytes: Long
+        ): Long = (maxHeapBytes / HEAP_BUDGET_DIVISOR)
+            .coerceAtLeast(maxPacketResourceBytes)
+            .coerceAtMost(MAX_BUDGET_BYTES.coerceAtLeast(maxPacketResourceBytes))
+    }
+}

app/src/main/java/com/bitchat/android/ui/ChatViewModel.kt

@@ -7,9 +7,14 @@ import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.bitchat.android.favorites.FavoritesChangeListener
 import com.bitchat.android.favorites.FavoritesPersistenceService
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.stateIn
 import com.bitchat.android.mesh.BluetoothMeshDelegate
 import com.bitchat.android.mesh.BluetoothMeshService
 import com.bitchat.android.mesh.MeshService
@@ -31,10 +36,12 @@ import com.bitchat.android.nostr.NdrOutOfBandPayload
 import com.bitchat.android.nostr.NdrOutOfBandRoutePolicy
 import com.bitchat.android.nostr.NostrEvent
 import com.bitchat.android.nostr.NostrIdentityBridge
+import com.bitchat.android.nostr.GeohashConversationRegistry
 import com.bitchat.android.protocol.BitchatPacket
 
 
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import com.bitchat.android.util.NotificationIntervalManager
 import kotlinx.coroutines.delay
 import java.util.Date
@@ -133,8 +140,12 @@ class ChatViewModel(
         messageManager,
         dataManager,
         noiseSessionDelegate,
-        hasReadReceiptBeenSent = seenMessageStore::hasReadReceiptBeenSent,
-        markMessageReadLocally = seenMessageStore::markReadLocally
+        hasReadReceiptBeenSent = { messageID ->
+            seenMessageStore.hasReadReceiptBeenSent(messageID)
+        },
+        markMessageReadLocally = { messageID ->
+            seenMessageStore.markReadLocally(messageID)
+        }
     )
     private val commandProcessor = CommandProcessor(state, messageManager, channelManager, privateChatManager)
     private val notificationManager = NotificationManager(
@@ -173,7 +184,9 @@ class ChatViewModel(
         onHapticFeedback = { ChatViewModelUtils.triggerHapticFeedback(application.applicationContext) },
         getMyPeerID = { mesh.myPeerID },
         getMeshService = { mesh },
-        markMessageReadLocally = seenMessageStore::markReadLocally
+        markMessageReadLocally = { messageID ->
+            seenMessageStore.markReadLocally(messageID)
+        }
     )
     
     // New Geohash architecture ViewModel (replaces God object service usage in UI path)
@@ -261,6 +274,57 @@ class ChatViewModel(
     val privateChats: StateFlow<Map<String, List<BitchatMessage>>> = state.privateChats
     val selectedPrivateChatPeer: StateFlow<String?> = state.selectedPrivateChatPeer
     val unreadPrivateMessages: StateFlow<Set<String>> = state.unreadPrivateMessages
+    internal val unreadConversations: StateFlow<List<UnreadConversationSummary>> = combine(
+        state.unreadPrivateMessages,
+        state.privateChats,
+        state.nickname,
+        state.connectedPeers
+    ) { unreadConversationIDs, chats, currentNickname, connectedPeerIDs ->
+        val seenStore = seenMessageStore
+        val connectedPeerIDSet = connectedPeerIDs.mapTo(mutableSetOf()) { it.lowercase() }
+        buildUnreadConversationSummaries(
+            unreadConversationIDs = unreadConversationIDs,
+            privateChats = chats,
+            currentUserIdentifiers = setOf(currentNickname, mesh.myPeerID),
+            canonicalize = ContactDirectory::canonicalConversationId,
+            isMessageRead = { message -> seenStore.hasBeenReadLocally(message.id) }
+        ).map { summary ->
+            val resolution = ContactDirectory.resolve(summary.conversationID)
+            val resolvedNostrPubkey = summary.nostrPubkey
+                ?: resolution.nostrPubkey?.let(ContactIdentityResolver::nostrPubkeyHex)
+            val aliases = buildSet {
+                addAll(summary.identityAliases)
+                add(summary.conversationID)
+                add(resolution.conversationID)
+                resolution.meshPeerID?.let(::add)
+                resolution.noiseKeyHex?.let(::add)
+                resolvedNostrPubkey
+                    ?.let(ContactIdentityResolver::nostrAliasForPubkey)
+                    ?.let(::add)
+            }.mapTo(mutableSetOf()) { it.lowercase() }
+
+            summary.copy(
+                displayName = resolution.displayName
+                    ?.takeUnless {
+                        it.isBlank() || it.equals("Unknown", ignoreCase = true)
+                    }
+                    ?: summary.displayName,
+                nostrPubkey = resolvedNostrPubkey,
+                identityAliases = aliases,
+                isConnected = aliases.any(connectedPeerIDSet::contains),
+                sourceGeohash = aliases
+                    .asSequence()
+                    .mapNotNull(GeohashConversationRegistry::get)
+                    .firstOrNull()
+            )
+        }
+    }
+        .flowOn(Dispatchers.IO)
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.Eagerly,
+            initialValue = emptyList()
+        )
     val joinedChannels: StateFlow<Set<String>> = state.joinedChannels
     val currentChannel: StateFlow<String?> = state.currentChannel
     val channelMessages: StateFlow<Map<String, List<BitchatMessage>>> = state.channelMessages
@@ -326,24 +390,27 @@ class ChatViewModel(
         }
         viewModelScope.launch {
             try { com.bitchat.android.services.AppStateStore.privateMessages.collect { byPeer ->
-                val canonicalChats = ContactDirectory.canonicalizePrivateChats(byPeer)
+                val (canonicalChats, unreadConversationIDs) = withContext(Dispatchers.IO) {
+                    val canonical = ContactDirectory.canonicalizePrivateChats(byPeer)
+                    val unread = try {
+                        val myNick = state.getNicknameValue().ifBlank { mesh.myPeerID }
+                        canonical
+                            .filterValues { messages ->
+                                messages.any { message ->
+                                    message.sender != myNick &&
+                                        message.sender != "system" &&
+                                        !seenMessageStore.hasBeenReadLocally(message.id)
+                                }
+                            }
+                            .keys
+                    } catch (_: Exception) {
+                        state.getUnreadPrivateMessagesValue()
+                    }
+                    canonical to unread
+                }
                 state.setPrivateChats(canonicalChats)
                 // Recompute unread set using SeenMessageStore for robustness across Activity recreation
-                try {
-                    val myNick = state.getNicknameValue() ?: mesh.myPeerID
-                    val unread = mutableSetOf<String>()
-                    canonicalChats.forEach { (peer, list) ->
-                        if (list.any { msg ->
-                                msg.sender != myNick &&
-                                    msg.sender != "system" &&
-                                    !seenMessageStore.hasBeenReadLocally(msg.id)
-                            }
-                        ) {
-                            unread.add(peer)
-                        }
-                    }
-                    state.setUnreadPrivateMessages(unread)
-                } catch (_: Exception) { }
+                state.setUnreadPrivateMessages(unreadConversationIDs)
             } } catch (_: Exception) { }
         }
         viewModelScope.launch {
@@ -493,15 +560,26 @@ class ChatViewModel(
     
     // MARK: - Private Chat Management (delegated)
     
-    fun startPrivateChat(peerID: String) {
+    suspend fun startPrivateChat(peerID: String) {
         // For geohash conversation keys, ensure DM subscription is active
         if (peerID.startsWith("nostr_")) {
             ensureGeohashDMSubscriptionIfNeeded(peerID)
         }
-        
-        val success = privateChatManager.startPrivateChat(peerID, mesh)
+
+        val (conversationID, success) = withContext(Dispatchers.IO) {
+            val canonicalID = ContactDirectory.canonicalConversationId(peerID)
+            val unreadAliases = matchingUnreadAliases(
+                unreadConversationIDs = state.getUnreadPrivateMessagesValue(),
+                canonicalConversationID = canonicalID,
+                canonicalize = ContactDirectory::canonicalConversationId
+            )
+            canonicalID to privateChatManager.startPrivateChat(
+                peerID = canonicalID,
+                meshService = mesh,
+                unreadAliases = unreadAliases
+            )
+        }
         if (success) {
-            val conversationID = ContactDirectory.canonicalConversationId(peerID)
             // Notify notification manager about current private chat
             setCurrentPrivateChatPeer(conversationID)
             // Clear notifications for this sender since user is now viewing the chat

app/src/main/java/com/bitchat/android/ui/GeohashPeopleList.kt

@@ -36,7 +36,8 @@ data class GeoPerson(
 fun GeohashPeopleList(
     viewModel: ChatViewModel,
     onTapPerson: () -> Unit,
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
+    excludedIdentityAliases: Set<String> = emptySet()
 ) {
     val geohashPeople by viewModel.geohashPeople.collectAsStateWithLifecycle()
     val selectedLocationChannel by viewModel.selectedLocationChannel.collectAsStateWithLifecycle()
@@ -77,9 +78,15 @@ fun GeohashPeopleList(
             geohashPeople
         }
     }
-    val sections = remember(peopleIncludingSelf, myHex, isTeleported, teleportedGeo) {
+    val visiblePeople = remember(peopleIncludingSelf, excludedIdentityAliases) {
+        peopleIncludingSelf.filterNot { person ->
+            val alias = "nostr_${person.id.take(16)}".lowercase()
+            alias in excludedIdentityAliases
+        }
+    }
+    val sections = remember(visiblePeople, myHex, isTeleported, teleportedGeo) {
         sectionGeohashPeople(
-            people = peopleIncludingSelf,
+            people = visiblePeople,
             myId = myHex,
             selfIsTeleported = isTeleported,
             teleportedIds = teleportedGeo

app/src/main/java/com/bitchat/android/ui/MediaSendingManager.kt

@@ -43,7 +43,7 @@ class MediaSendingManager(
         get() = getMeshService()
     companion object {
         private const val TAG = "MediaSendingManager"
-        private const val MAX_FILE_SIZE = com.bitchat.android.util.AppConstants.Media.MAX_FILE_SIZE_BYTES // 50MB limit
+        private const val MAX_FILE_SIZE = com.bitchat.android.util.AppConstants.Media.MAX_FILE_SIZE_BYTES
         private const val PENDING_PRIVATE_MEDIA_TIMEOUT_MS = 15_000L
     }
 
@@ -81,6 +81,46 @@ class MediaSendingManager(
     private var automaticRetryRequestedFor: String? = null
     private var pendingAutomaticTimeoutRequestId: String? = null
 
+    /**
+     * Enforce the send-size cap with a user-visible failure posted to the
+     * conversation the user is sending from. Returns true if the file is
+     * oversized and the send was aborted.
+     */
+    private fun rejectIfOversized(
+        file: java.io.File,
+        toPeerIDOrNull: String?,
+        channelOrNull: String?
+    ): Boolean {
+        val size = file.length()
+        if (size <= MAX_FILE_SIZE) return false
+        Log.e(TAG, "❌ File too large: $size bytes (max: $MAX_FILE_SIZE)")
+        val sizeMb = size / (1024 * 1024)
+        val maxMb = MAX_FILE_SIZE / (1024 * 1024)
+        val text = "cannot send ${file.name}: file is too large (${sizeMb} MB, max $maxMb MB)"
+        when {
+            toPeerIDOrNull != null -> {
+                val sys = BitchatMessage(
+                    sender = "system",
+                    content = text,
+                    timestamp = Date(),
+                    isRelay = false
+                )
+                messageManager.addPrivateMessageNoUnread(toPeerIDOrNull, sys)
+            }
+            channelOrNull != null -> {
+                val sys = BitchatMessage(
+                    sender = "system",
+                    content = text,
+                    timestamp = Date(),
+                    isRelay = false
+                )
+                messageManager.addChannelMessage(channelOrNull, sys)
+            }
+            else -> messageManager.addSystemMessage(text)
+        }
+        return true
+    }
+
     /**
      * Send a voice note (audio file)
      */
@@ -103,8 +143,7 @@ class MediaSendingManager(
                     return@withContext null
                 }
 
-                if (file.length() > MAX_FILE_SIZE) {
-                    Log.e(TAG, "File too large: ${file.length()} bytes (max: $MAX_FILE_SIZE)")
+                if (rejectIfOversized(file, toPeerIDOrNull, channelOrNull)) {
                     return@withContext null
                 }
 
@@ -148,8 +187,7 @@ class MediaSendingManager(
                     return@withContext null
                 }
 
-                if (file.length() > MAX_FILE_SIZE) {
-                    Log.e(TAG, "File too large: ${file.length()} bytes (max: $MAX_FILE_SIZE)")
+                if (rejectIfOversized(file, toPeerIDOrNull, channelOrNull)) {
                     return@withContext null
                 }
 
@@ -193,8 +231,7 @@ class MediaSendingManager(
                     return@withContext null
                 }
 
-                if (file.length() > MAX_FILE_SIZE) {
-                    Log.e(TAG, "File too large: ${file.length()} bytes (max: $MAX_FILE_SIZE)")
+                if (rejectIfOversized(file, toPeerIDOrNull, channelOrNull)) {
                     return@withContext null
                 }
 

app/src/main/java/com/bitchat/android/ui/MeshPeerListSheet.kt

@@ -88,9 +88,17 @@ fun MeshPeerListSheet(
     val peerRSSI by viewModel.peerRSSI.collectAsStateWithLifecycle()
     val selectedLocationChannel by viewModel.selectedLocationChannel.collectAsStateWithLifecycle()
     val geohashPeople by viewModel.geohashPeople.collectAsStateWithLifecycle()
+    val unreadConversations by viewModel.unreadConversations.collectAsStateWithLifecycle()
     val geohashPeopleCount = geohashPeople.size
     val wifiAwareConnected by com.bitchat.android.wifiaware.WifiAwareController.connectedPeers.collectAsStateWithLifecycle()
     val wifiAwarePeerIDs = remember(wifiAwareConnected) { wifiAwareConnected.keys.toSet() }
+    val unreadIdentityAliases = remember(unreadConversations) {
+        unreadConversations
+            .flatMapTo(mutableSetOf()) { it.identityAliases }
+    }
+    val visibleConnectedPeers = connectedPeers.filterNot { peerID ->
+        peerID.lowercase() in unreadIdentityAliases
+    }
 
     // Bottom sheet state
     val sheetState = rememberModalBottomSheetState(
@@ -123,7 +131,21 @@ fun MeshPeerListSheet(
                 ) {
                     val peopleCount = when (selectedLocationChannel) {
                         is ChannelID.Location -> geohashPeopleCount
-                        else -> connectedPeers.count { it != viewModel.myPeerID }
+                        else -> visibleConnectedPeers.count { it != viewModel.myPeerID }
+                    }
+
+                    if (unreadConversations.isNotEmpty()) {
+                        item(key = "unread_private_messages_section") {
+                            UnreadDirectMessagesSection(
+                                conversations = unreadConversations,
+                                viewModel = viewModel,
+                                onPrivateChatStart = { conversationID ->
+                                    viewModel.showPrivateChatSheet(conversationID)
+                                    onDismiss()
+                                },
+                                modifier = Modifier.padding(top = 8.dp)
+                            )
+                        }
                     }
 
                     // Channels section
@@ -133,7 +155,9 @@ fun MeshPeerListSheet(
                                 SheetIconSectionHeader(
                                     iconRes = R.drawable.ic_spec_chat_bubbles,
                                     title = stringResource(R.string.channels),
-                                    modifier = Modifier.padding(top = 8.dp)
+                                    modifier = Modifier.padding(
+                                        top = if (unreadConversations.isNotEmpty()) 20.dp else 8.dp
+                                    )
                                 )
                                 Surface(
                                     modifier = Modifier
@@ -185,8 +209,12 @@ fun MeshPeerListSheet(
                                 GeohashPeopleList(
                                     viewModel = viewModel,
                                     onTapPerson = onDismiss,
+                                    excludedIdentityAliases = unreadIdentityAliases,
                                     modifier = Modifier.padding(
-                                        top = if (joinedChannels.isNotEmpty()) 20.dp else 8.dp
+                                        top = if (
+                                            joinedChannels.isNotEmpty() ||
+                                            unreadConversations.isNotEmpty()
+                                        ) 20.dp else 8.dp
                                     )
                                 )
                             }
@@ -194,9 +222,12 @@ fun MeshPeerListSheet(
                             else -> {
                                 PeopleSection(
                                     modifier = Modifier.padding(
-                                        top = if (joinedChannels.isNotEmpty()) 20.dp else 8.dp
+                                        top = if (
+                                            joinedChannels.isNotEmpty() ||
+                                            unreadConversations.isNotEmpty()
+                                        ) 20.dp else 8.dp
                                     ),
-                                    connectedPeers = connectedPeers,
+                                    connectedPeers = visibleConnectedPeers,
                                     peerNicknames = peerNicknames,
                                     peerRSSI = peerRSSI,
                                     nickname = nickname,
@@ -204,6 +235,7 @@ fun MeshPeerListSheet(
                                     selectedPrivatePeer = selectedPrivatePeer,
                                     wifiAwarePeerIDs = wifiAwarePeerIDs,
                                     peopleCount = peopleCount,
+                                    excludedIdentityAliases = unreadIdentityAliases,
                                     viewModel = viewModel,
                                     onPrivateChatStart = { peerID ->
                                         viewModel.showPrivateChatSheet(peerID)
@@ -318,6 +350,7 @@ fun PeopleSection(
     selectedPrivatePeer: String?,
     wifiAwarePeerIDs: Set<String> = emptySet(),
     peopleCount: Int = 0,
+    excludedIdentityAliases: Set<String> = emptySet(),
     viewModel: ChatViewModel,
     onPrivateChatStart: (String) -> Unit
 ) {
@@ -433,8 +466,6 @@ fun PeopleSection(
         )
         
         // Build a map of base name counts across all people shown in the list (connected + offline + nostr)
-        val hex64Regex = Regex("^[0-9a-fA-F]{64}$")
-
         // Helper to compute display name used for a given key
         fun computeDisplayNameForPeerId(key: String): String {
             return if (key == nickname) "You" else (peerNicknames[key] ?: (privateChats[key]?.lastOrNull()?.sender ?: key.take(12)))
@@ -453,33 +484,28 @@ fun PeopleSection(
         val offlineFavorites = FavoritesPersistenceService.shared.getOurFavorites()
         offlineFavorites.forEach { fav ->
             val favPeerID = ContactIdentityResolver.noiseKeyHex(fav.peerNoisePublicKey)
-            if (!isFavoriteMappedToConnected(fav)) {
+            if (
+                favPeerID.lowercase() !in excludedIdentityAliases &&
+                !isFavoriteMappedToConnected(fav)
+            ) {
                 val dn = peerNicknames[favPeerID] ?: fav.peerNickname
                 val (b, _) = splitSuffix(dn)
                 if (b != "You") baseNameCounts[b] = (baseNameCounts[b] ?: 0) + 1
             }
         }
 
-        // Nostr-only conversations
-        val connectedIds = sortedPeers.toSet()
-        privateChats.keys
-            .filter { key ->
-                (key.startsWith("nostr_") || hex64Regex.matches(key)) &&
-                        !connectedIds.contains(key) &&
-                        !connectedNoiseHexes.contains(key.lowercase())
-            }
-            .forEach { convKey ->
-                val dn = peerNicknames[convKey] ?: (privateChats[convKey]?.lastOrNull()?.sender ?: convKey.take(12))
-                val (b, _) = splitSuffix(dn)
-                if (b != "You") baseNameCounts[b] = (baseNameCounts[b] ?: 0) + 1
-            }
-
         // Every row this card will show, in final order, so the animated list can key on identity
         // and animate reordering. Offline favourites are appended after the connected peers.
         // Collected once for the whole card rather than once per row.
         val directMap by viewModel.peerDirect.collectAsStateWithLifecycle()
 
-        val offlineFavoriteRows = offlineFavorites.filterNot { isFavoriteMappedToConnected(it) }
+        val offlineFavoriteRows = offlineFavorites.filterNot { favorite ->
+            val favoriteNoiseKey = ContactIdentityResolver.noiseKeyHex(
+                favorite.peerNoisePublicKey
+            )
+            favoriteNoiseKey.lowercase() in excludedIdentityAliases ||
+                isFavoriteMappedToConnected(favorite)
+        }
         val rowKeys: List<String> = sortedPeers +
             offlineFavoriteRows.map { ContactIdentityResolver.noiseKeyHex(it.peerNoisePublicKey) }
 
@@ -589,6 +615,126 @@ fun PeopleSection(
     }
 }
 
+@Composable
+private fun UnreadDirectMessagesSection(
+    conversations: List<UnreadConversationSummary>,
+    viewModel: ChatViewModel,
+    onPrivateChatStart: (String) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    val palette = LocalBitchatPalette.current
+    val colorScheme = MaterialTheme.colorScheme
+
+    Column(modifier = modifier) {
+        SheetIconSectionHeader(
+            iconRes = R.drawable.ic_spec_envelope,
+            title = stringResource(R.string.cd_unread_private_messages)
+        )
+
+        Surface(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = AboutHorizontalPadding)
+                .padding(top = 10.dp),
+            color = colorScheme.surface,
+            shape = AboutCardShape
+        ) {
+            AnimatedRowColumn(
+                items = conversations,
+                key = { it.conversationID }
+            ) { index, conversation ->
+                Column {
+                    if (index > 0) SheetCardDivider()
+
+                    val subtitle = when {
+                        conversation.sourceGeohash != null -> "#${conversation.sourceGeohash}"
+                        conversation.transport == DirectMessageTransport.NOSTR ->
+                            stringResource(R.string.cd_reachable_via_nostr)
+                        !conversation.isConnected ->
+                            stringResource(R.string.cd_offline_mesh_chat)
+                        else -> null
+                    }
+                    val peerIdentity = conversation.nostrPubkey
+                        ?.let(viewModel::peerIdentityForNostrPubkey)
+                        ?: viewModel.peerIdentityForMeshPeer(conversation.conversationID)
+                    val assignedColor = colorForPeer(peerIdentity, palette)
+                    val (baseNameRaw, suffix) = splitSuffix(conversation.displayName)
+
+                    Row(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .clickable {
+                                onPrivateChatStart(conversation.conversationID)
+                            }
+                            .padding(
+                                horizontal = SheetRowHorizontal,
+                                vertical = SheetRowVertical
+                            ),
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        Box(
+                            modifier = Modifier.size(SheetRowLeadingSlot),
+                            contentAlignment = Alignment.Center
+                        ) {
+                            Icon(
+                                painter = painterResource(R.drawable.ic_spec_envelope),
+                                contentDescription = stringResource(R.string.cd_unread_message),
+                                modifier = Modifier.size(PeerRowIconSize),
+                                tint = palette.accentOrange
+                            )
+                        }
+
+                        Spacer(modifier = Modifier.width(SheetRowLeadingGutter))
+
+                        Column(modifier = Modifier.weight(1f)) {
+                            Row(
+                                verticalAlignment = Alignment.CenterVertically,
+                                horizontalArrangement = Arrangement.spacedBy(4.dp)
+                            ) {
+                                Text(
+                                    text = truncateNickname(baseNameRaw),
+                                    fontFamily = BitchatFontFamily,
+                                    fontSize = 14.sp,
+                                    fontWeight = FontWeight.Medium,
+                                    color = assignedColor,
+                                    maxLines = 1,
+                                    overflow = TextOverflow.Ellipsis
+                                )
+
+                                if (suffix.isNotEmpty()) {
+                                    Text(
+                                        text = suffix,
+                                        fontFamily = BitchatFontFamily,
+                                        fontSize = 14.sp,
+                                        fontWeight = FontWeight.Medium,
+                                        color = assignedColor.copy(alpha = SUFFIX_ALPHA)
+                                    )
+                                }
+                            }
+
+                            if (subtitle != null) {
+                                Text(
+                                    text = subtitle,
+                                    fontFamily = BitchatFontFamily,
+                                    fontSize = 11.sp,
+                                    color = palette.textTertiary,
+                                    maxLines = 1,
+                                    overflow = TextOverflow.Ellipsis
+                                )
+                            }
+                        }
+
+                        UnreadBadge(
+                            count = conversation.unreadCount,
+                            colorScheme = colorScheme
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
 @Composable
 private fun PeerItem(
     peerID: String,

app/src/main/java/com/bitchat/android/ui/MessageManager.kt

@@ -153,11 +153,17 @@ class MessageManager(private val state: ChatState) {
         state.setPrivateChats(updatedChats)
     }
     
-    fun clearPrivateUnreadMessages(peerID: String) {
+    fun clearPrivateUnreadMessages(
+        peerID: String,
+        aliases: Set<String> = emptySet()
+    ) {
         val conversationID = ContactDirectory.canonicalConversationId(peerID)
         val updatedUnread = state.getUnreadPrivateMessagesValue().toMutableSet()
-        updatedUnread.remove(peerID)
-        updatedUnread.remove(conversationID)
+        val normalizedAliases = (aliases + peerID + conversationID)
+            .mapTo(mutableSetOf()) { it.lowercase() }
+        updatedUnread.removeAll { unreadID ->
+            unreadID.lowercase() in normalizedAliases
+        }
         state.setUnreadPrivateMessages(updatedUnread)
     }
     

app/src/main/java/com/bitchat/android/ui/PrivateChatManager.kt

@@ -49,7 +49,11 @@ class PrivateChatManager(
 
     // MARK: - Private Chat Lifecycle
 
-    fun startPrivateChat(peerID: String, meshService: MeshService): Boolean {
+    fun startPrivateChat(
+        peerID: String,
+        meshService: MeshService,
+        unreadAliases: Set<String> = emptySet()
+    ): Boolean {
         val conversationID = ContactDirectory.canonicalConversationId(peerID)
         val route = ContactDirectory.resolve(conversationID)
         val meshPeerID = route.meshPeerID ?: peerID.takeIf { ContactIdentityResolver.isMeshPeerId(it) }
@@ -77,7 +81,7 @@ class PrivateChatManager(
         state.setSelectedPrivateChatPeer(conversationID)
 
         // Clear unread
-        messageManager.clearPrivateUnreadMessages(conversationID)
+        messageManager.clearPrivateUnreadMessages(conversationID, unreadAliases)
 
         // Initialize chat if needed
         messageManager.initializePrivateChat(conversationID)

app/src/main/java/com/bitchat/android/ui/UnreadConversationSummary.kt

@@ -0,0 +1,105 @@
+package com.bitchat.android.ui
+
+import com.bitchat.android.model.BitchatMessage
+
+internal enum class DirectMessageTransport {
+    MESH,
+    NOSTR
+}
+
+/**
+ * Presence-independent presentation state for an unread private conversation.
+ *
+ * A conversation remains in this model until it is read, even when none of its identities are in
+ * the current mesh or geohash participant lists.
+ */
+internal data class UnreadConversationSummary(
+    val conversationID: String,
+    val displayName: String,
+    val unreadCount: Int,
+    val latestMessageAt: Long,
+    val transport: DirectMessageTransport,
+    val nostrPubkey: String?,
+    val identityAliases: Set<String>,
+    val isConnected: Boolean = false,
+    val sourceGeohash: String? = null
+)
+
+internal fun buildUnreadConversationSummaries(
+    unreadConversationIDs: Set<String>,
+    privateChats: Map<String, List<BitchatMessage>>,
+    currentUserIdentifiers: Set<String>,
+    canonicalize: (String) -> String,
+    isMessageRead: (BitchatMessage) -> Boolean
+): List<UnreadConversationSummary> {
+    if (unreadConversationIDs.isEmpty()) return emptyList()
+
+    val normalizedCurrentUserIdentifiers = currentUserIdentifiers.filterTo(mutableSetOf()) {
+        it.isNotBlank()
+    }
+    val canonicalUnreadIDs = unreadConversationIDs
+        .mapTo(linkedSetOf()) { canonicalize(it) }
+    val unreadAliasesByCanonicalID = unreadConversationIDs.groupBy(canonicalize)
+    val messagesByCanonicalID = linkedMapOf<String, MutableList<BitchatMessage>>()
+
+    privateChats.forEach { (conversationID, messages) ->
+        val canonicalID = canonicalize(conversationID)
+        messagesByCanonicalID.getOrPut(canonicalID) { mutableListOf() }.addAll(messages)
+    }
+
+    return canonicalUnreadIDs.map { conversationID ->
+        val messages = messagesByCanonicalID[conversationID]
+            .orEmpty()
+            .distinctBy { it.id }
+        val incomingMessages = messages.filterNot {
+            it.sender in normalizedCurrentUserIdentifiers
+        }
+        val unreadIncomingMessages = incomingMessages.filterNot(isMessageRead)
+        val latestMessage = (unreadIncomingMessages.ifEmpty { incomingMessages })
+            .maxWithOrNull(compareBy<BitchatMessage> { it.timestamp.time }.thenBy { it.id })
+        val aliases = unreadAliasesByCanonicalID[conversationID].orEmpty()
+        val nostrPubkey = latestMessage?.senderNostrPubkey
+        val isNostrConversation = nostrPubkey != null ||
+            aliases.any(::isNostrConversationID) ||
+            isNostrConversationID(conversationID)
+
+        UnreadConversationSummary(
+            conversationID = conversationID,
+            displayName = latestMessage
+                ?.sender
+                ?.takeIf { it.isNotBlank() }
+                ?: conversationID.take(12),
+            unreadCount = unreadIncomingMessages.size.coerceAtLeast(1),
+            latestMessageAt = latestMessage?.timestamp?.time ?: Long.MIN_VALUE,
+            transport = if (isNostrConversation) {
+                DirectMessageTransport.NOSTR
+            } else {
+                DirectMessageTransport.MESH
+            },
+            nostrPubkey = nostrPubkey,
+            identityAliases = (aliases + conversationID)
+                .mapTo(mutableSetOf()) { it.lowercase() }
+        )
+    }.sortedWith(
+        compareByDescending<UnreadConversationSummary> { it.latestMessageAt }
+            .thenBy { it.displayName.lowercase() }
+            .thenBy { it.conversationID }
+    )
+}
+
+private fun isNostrConversationID(value: String): Boolean =
+    value.startsWith("nostr_") || value.startsWith("nostr:")
+
+internal fun matchingUnreadAliases(
+    unreadConversationIDs: Set<String>,
+    canonicalConversationID: String,
+    canonicalize: (String) -> String
+): Set<String> {
+    val normalizedCanonicalID = canonicalConversationID.lowercase()
+    return unreadConversationIDs
+        .filterTo(mutableSetOf()) { unreadID ->
+            canonicalize(unreadID).equals(normalizedCanonicalID, ignoreCase = true)
+        }
+        .plus(canonicalConversationID)
+        .mapTo(mutableSetOf()) { it.lowercase() }
+}

app/src/main/java/com/bitchat/android/ui/theme/BitchatPalette.kt

@@ -41,10 +41,11 @@ data class BitchatPalette(
     val accentPurple: Color,
 
     // MARK: - Deterministic peer colors
-    /** Chroma applied after deriving a peer's stable hue. */
-    val peerColorSaturation: Float,
-    /** Brightness applied after deriving a peer's stable hue. */
-    val peerColorValue: Float,
+    /**
+     * Saturation/value applied after deriving a peer's stable hue. Swap this when adding a
+     * new theme — see [PeerColorStyle] for contrast guidelines.
+     */
+    val peerColors: PeerColorStyle,
 )
 
 val DarkBitchatPalette = BitchatPalette(
@@ -56,8 +57,7 @@ val DarkBitchatPalette = BitchatPalette(
     textTertiary = Color(0xFF6B776B),
     accentOrange = Color(0xFFFF9F0A),
     accentPurple = Color(0xFFBF5AF2),
-    peerColorSaturation = 1f,
-    peerColorValue = 1f,
+    peerColors = PeerColorStyle.Dark,
 )
 
 val LightBitchatPalette = BitchatPalette(
@@ -69,8 +69,7 @@ val LightBitchatPalette = BitchatPalette(
     textTertiary = Color(0xFF757F75),
     accentOrange = Color(0xFFFF9500),
     accentPurple = Color(0xFFAF52DE),
-    peerColorSaturation = 0.85f,
-    peerColorValue = 0.45f,
+    peerColors = PeerColorStyle.Light,
 )
 
 val LocalBitchatPalette = staticCompositionLocalOf { DarkBitchatPalette }

app/src/main/java/com/bitchat/android/ui/theme/PeerColors.kt

@@ -1,9 +1,36 @@
 package com.bitchat.android.ui.theme
 
+import androidx.compose.runtime.Immutable
 import androidx.compose.ui.graphics.Color
 import com.bitchat.android.ui.PeerIdentity
 import kotlin.math.abs
 
+/**
+ * Theme-specific chroma applied after a peer's stable hue is derived.
+ *
+ * Hue stays identity-stable across themes (and byte-identical to iOS). Only saturation
+ * and value change so peer labels remain readable on each background.
+ *
+ * Guidelines when adding a future theme:
+ * - Dim / dark backgrounds: keep [value] high so colors are not lost against the surface;
+ *   prefer muted [saturation] over neon.
+ * - Light backgrounds: keep [value] moderate-low so colors are not blinding; avoid
+ *   near-full saturation.
+ */
+@Immutable
+data class PeerColorStyle(
+    val saturation: Float,
+    val value: Float,
+) {
+    companion object {
+        /** Soft pastels that stay bright enough on near-black chat surfaces. */
+        val Dark = PeerColorStyle(saturation = 0.55f, value = 0.82f)
+
+        /** Deeper, less saturated tones that stay readable on near-white surfaces. */
+        val Light = PeerColorStyle(saturation = 0.70f, value = 0.42f)
+    }
+}
+
 /**
  * The single identity-to-color boundary used by chat, people sheets, and mentions.
  *
@@ -22,9 +49,10 @@ fun colorForPeer(identity: PeerIdentity, palette: BitchatPalette): Color {
         hue = (hue + 0.12) % 1.0
     }
 
+    val style = palette.peerColors
     return Color.hsv(
         hue = (hue * 360).toFloat(),
-        saturation = palette.peerColorSaturation,
-        value = palette.peerColorValue
+        saturation = style.saturation,
+        value = style.value
     )
 }

app/src/main/java/com/bitchat/android/util/AppConstants.kt

@@ -131,7 +131,9 @@ object AppConstants {
     }
 
     object Media {
-        const val MAX_FILE_SIZE_BYTES: Long = 50L * 1024 * 1024
+        // A file is currently encoded into one protocol payload before BLE fragmentation.
+        // Reserve room for maximum filename/MIME TLVs and encryption envelope overhead.
+        const val MAX_FILE_SIZE_BYTES: Long = (10L * 1024 * 1024) - (132L * 1024)
     }
 
     object Services {

app/src/test/java/com/bitchat/android/protocol/BinaryProtocolTest.kt

@@ -1,5 +1,6 @@
 package com.bitchat.android.protocol
 
+import com.bitchat.android.model.BitchatFilePacket
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertArrayEquals
 import org.junit.Assert.assertFalse
@@ -7,9 +8,11 @@ import org.junit.Assert.assertNotNull
 import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Test
+import java.io.ByteArrayOutputStream
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import java.util.Random
+import java.util.zip.Deflater
 
 class BinaryProtocolTest {
 
@@ -987,6 +990,315 @@ class BinaryProtocolTest {
         assertNull("v2 compression bomb (ratio > 50,000:1) must be rejected", result)
     }
 
+    @Test
+    fun `v2 expanded payload at exact maximum passes bound without allocating output`() {
+        val max = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = max,
+            compressedData = ByteArray(256) { it.toByte() }
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, requestedSize ->
+            calls += 1
+            assertEquals(max, requestedSize)
+            null // Prove the boundary reached this seam without allocating a 10 MiB result.
+        }
+
+        assertNull("The test decompressor deliberately returns no payload", result)
+        assertEquals(1, calls)
+    }
+
+    @Test
+    fun `v2 expanded payload above maximum never reaches decompressor`() {
+        val max = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = max + 1,
+            compressedData = ByteArray(256) { it.toByte() }
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, _ ->
+            calls += 1
+            byteArrayOf(0x42)
+        }
+
+        assertNull("An oversized expansion must be rejected before inflation", result)
+        assertEquals("The decompressor must not be invoked", 0, calls)
+    }
+
+    @Test
+    fun `v2 negative expanded payload never reaches decompressor`() {
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = -1,
+            compressedData = byteArrayOf(0x03)
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, _ ->
+            calls += 1
+            byteArrayOf(0x42)
+        }
+
+        assertNull("A negative expansion must be rejected before inflation", result)
+        assertEquals("The decompressor must not be invoked", 0, calls)
+    }
+
+    @Test
+    fun `zero expanded payload never reaches decompressor`() {
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = 0,
+            compressedData = rawDeflate(ByteArray(0))
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, _ ->
+            calls += 1
+            ByteArray(0)
+        }
+
+        assertNull("Compressed zero-length payloads are non-canonical and must be rejected", result)
+        assertEquals("The decompressor must not be invoked", 0, calls)
+    }
+
+    @Test
+    fun `empty compressed body never reaches decompressor`() {
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = 128,
+            compressedData = ByteArray(0)
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, _ ->
+            calls += 1
+            ByteArray(128)
+        }
+
+        assertNull("A compressed payload must contain deflate bytes", result)
+        assertEquals("The decompressor must not be invoked", 0, calls)
+    }
+
+    @Test
+    fun `v1 unsigned maximum expanded size reaches decompressor`() {
+        val originalSize = 0xFFFF
+        val raw = compressedPacket(
+            version = 1u,
+            originalSize = originalSize,
+            compressedData = byteArrayOf(0x01, 0x02)
+        )
+        var calls = 0
+
+        val result = BinaryProtocol.decodeForTesting(raw) { _, requestedSize ->
+            calls += 1
+            assertEquals(originalSize, requestedSize)
+            null
+        }
+
+        assertNull("The test decompressor deliberately returns no payload", result)
+        assertEquals(1, calls)
+    }
+
+    @Test
+    fun `compression utility rejects invalid expansion sizes directly`() {
+        val max = com.bitchat.android.util.AppConstants.Protocol.MAX_PAYLOAD_LENGTH
+
+        assertNull(CompressionUtil.decompress(ByteArray(0), 1))
+        assertNull(CompressionUtil.decompress(rawDeflate(ByteArray(0)), 0))
+        assertNull(CompressionUtil.decompress(byteArrayOf(0x03), -1))
+        assertNull(CompressionUtil.decompress(byteArrayOf(0x03), max + 1))
+    }
+
+    @Test
+    fun `raw deflate expands only when size and stream completion are exact`() {
+        val payload = ByteArray(4_096) { index -> (index % 17).toByte() }
+        val compressed = rawDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = payload.size, compressedData = compressed)
+        )
+
+        assertNotNull(decoded)
+        assertArrayEquals(payload, decoded!!.payload)
+    }
+
+    @Test
+    fun `zlib wrapped payload remains compatible when size and stream completion are exact`() {
+        val payload = ByteArray(4_096) { index -> (index % 23).toByte() }
+        val compressed = zlibDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = payload.size, compressedData = compressed)
+        )
+
+        assertNotNull(decoded)
+        assertArrayEquals(payload, decoded!!.payload)
+    }
+
+    @Test
+    fun `raw deflate with zlib-looking prefix falls back after non-exact zlib parse`() {
+        val payload = ByteArray(29) { index -> (index + 1).toByte() }
+        val compressed = byteArrayOf(
+            0x08, // non-final raw stored block; also zlib CMF
+            0x1d, 0x00, // LEN = 29; 0x08 0x1d passes the RFC 1950 header check
+            0xe2.toByte(), 0xff.toByte() // one's complement of LEN
+        ) + payload + byteArrayOf(0x03, 0x00) // final empty fixed-Huffman block
+
+        assertArrayEquals(payload, CompressionUtil.decompress(compressed, payload.size))
+    }
+
+    @Test
+    fun `under-declared zlib expansion is rejected by fallback`() {
+        val payload = ByteArray(4_096) { 0x51 }
+        val compressed = zlibDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = 128, compressedData = compressed)
+        )
+
+        assertNull("Zlib fallback must reject output beyond the declaration", decoded)
+    }
+
+    @Test
+    fun `over-declared zlib expansion is rejected by fallback`() {
+        val payload = ByteArray(128) { 0x52 }
+        val compressed = zlibDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = 256, compressedData = compressed)
+        )
+
+        assertNull("Zlib fallback must reject output shorter than the declaration", decoded)
+    }
+
+    @Test
+    fun `truncated zlib stream is rejected by fallback`() {
+        val payload = ByteArray(4_096) { index -> (index % 29).toByte() }
+        val compressed = zlibDeflate(payload)
+        val truncated = compressed.copyOf(compressed.size - 1)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = payload.size, compressedData = truncated)
+        )
+
+        assertNull("Zlib fallback must require the stream end marker and checksum", decoded)
+    }
+
+    @Test
+    fun `zlib stream with trailing bytes is rejected by fallback`() {
+        val payload = ByteArray(4_096) { index -> (index % 13).toByte() }
+        val compressedWithTrailingByte = zlibDeflate(payload) + byteArrayOf(0x00)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(
+                version = 2u,
+                originalSize = payload.size,
+                compressedData = compressedWithTrailingByte
+            )
+        )
+
+        assertNull("Zlib fallback must consume the complete input and nothing more", decoded)
+    }
+
+    @Test
+    fun `under-declared raw expansion is rejected even when output buffer fills`() {
+        val payload = ByteArray(4_096) { 0x41 }
+        val compressed = rawDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = 128, compressedData = compressed)
+        )
+
+        assertNull("Inflater must be finished, not merely fill the declared buffer", decoded)
+    }
+
+    @Test
+    fun `over-declared raw expansion is rejected instead of returning a prefix`() {
+        val payload = ByteArray(128) { 0x42 }
+        val compressed = rawDeflate(payload)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = 256, compressedData = compressed)
+        )
+
+        assertNull("The expanded byte count must equal the declaration", decoded)
+    }
+
+    @Test
+    fun `truncated raw stream is rejected even if all declared bytes were emitted`() {
+        val payload = ByteArray(4_096) { index -> (index % 31).toByte() }
+        val compressed = rawDeflate(payload)
+        val truncated = compressed.copyOf(compressed.size - 1)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(version = 2u, originalSize = payload.size, compressedData = truncated)
+        )
+
+        assertNull("A stream without its end marker must not be accepted", decoded)
+    }
+
+    @Test
+    fun `raw stream with trailing bytes is rejected`() {
+        val payload = ByteArray(4_096) { index -> (index % 19).toByte() }
+        val compressedWithTrailingByte = rawDeflate(payload) + byteArrayOf(0x00)
+
+        val decoded = BinaryProtocol.decode(
+            compressedPacket(
+                version = 2u,
+                originalSize = payload.size,
+                compressedData = compressedWithTrailingByte
+            )
+        )
+
+        assertNull("Trailing bytes after a complete stream must not be accepted", decoded)
+    }
+
+    @Test
+    fun `decoder rejects a decompressor result shorter than its declaration`() {
+        val raw = compressedPacket(
+            version = 2u,
+            originalSize = 128,
+            compressedData = ByteArray(16) { it.toByte() }
+        )
+
+        val decoded = BinaryProtocol.decodeForTesting(raw) { _, _ -> byteArrayOf(0x01) }
+
+        assertNull("BinaryProtocol must independently enforce the declared expanded size", decoded)
+    }
+
+    @Test
+    fun `new sender refuses legacy 11 MiB public file transfer before transmission`() {
+        val content = ByteArray(11 * 1024 * 1024) { 0x41 }
+        val filePayload = BitchatFilePacket(
+            fileName = "legacy-11m.bin",
+            fileSize = content.size.toLong(),
+            mimeType = "application/octet-stream",
+            content = content
+        ).encode()
+        assertNotNull(filePayload)
+
+        val encoded = BinaryProtocol.encode(
+            BitchatPacket(
+                version = 2u,
+                type = MessageType.FILE_TRANSFER.value,
+                senderID = hexToBytes(senderHex),
+                recipientID = SpecialRecipients.BROADCAST,
+                timestamp = fixedTimestamp,
+                payload = filePayload!!,
+                ttl = 5u
+            ),
+            padding = false
+        )
+        assertNull(
+            "Sender and receiver must enforce the same expanded-payload ceiling",
+            encoded
+        )
+    }
+
     /**
      * Compression bomb is rejected
      *
@@ -1163,6 +1475,59 @@ class BinaryProtocolTest {
         return result
     }
 
+    private fun compressedPacket(
+        version: UByte,
+        originalSize: Int,
+        compressedData: ByteArray,
+        type: UByte = MessageType.MESSAGE.value
+    ): ByteArray {
+        val originalSizeFieldBytes = if (version >= 2u.toUByte()) 4 else 2
+        val payloadLength = originalSizeFieldBytes + compressedData.size
+        val headerSize = if (version >= 2u.toUByte()) 16 else 14
+        val buffer = ByteBuffer.allocate(headerSize + 8 + payloadLength).apply {
+            order(ByteOrder.BIG_ENDIAN)
+            put(version.toByte())
+            put(type.toByte())
+            put(5.toByte())
+            putLong(fixedTimestamp.toLong())
+            put(BinaryProtocol.Flags.IS_COMPRESSED.toByte())
+            if (version >= 2u.toUByte()) {
+                putInt(payloadLength)
+            } else {
+                putShort(payloadLength.toShort())
+            }
+            put(hexToBytes(senderHex))
+            if (version >= 2u.toUByte()) {
+                putInt(originalSize)
+            } else {
+                putShort(originalSize.toShort())
+            }
+            put(compressedData)
+        }
+        return buffer.array()
+    }
+
+    private fun rawDeflate(data: ByteArray): ByteArray = deflate(data, nowrap = true)
+
+    private fun zlibDeflate(data: ByteArray): ByteArray = deflate(data, nowrap = false)
+
+    private fun deflate(data: ByteArray, nowrap: Boolean): ByteArray {
+        val deflater = Deflater(Deflater.DEFAULT_COMPRESSION, nowrap)
+        return try {
+            deflater.setInput(data)
+            deflater.finish()
+            val output = ByteArrayOutputStream()
+            val buffer = ByteArray(1_024)
+            while (!deflater.finished()) {
+                val count = deflater.deflate(buffer)
+                output.write(buffer, 0, count)
+            }
+            output.toByteArray()
+        } finally {
+            deflater.end()
+        }
+    }
+
     private fun makePacket(
         version: UByte = 1u,
         type: UByte = MessageType.MESSAGE.value,

app/src/test/java/com/bitchat/android/protocol/DecompressionResourcePoolTest.kt

@@ -0,0 +1,117 @@
+package com.bitchat.android.protocol
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+
+class DecompressionResourcePoolTest {
+    @Test
+    fun `small reservations run concurrently and next waits only when budget is full`() {
+        val pool = DecompressionResourcePool(
+            budgetBytes = 2_000,
+            unitBytes = 1_000,
+            waitTimeoutMs = 2_000
+        )
+        val executor = Executors.newFixedThreadPool(3)
+        val entered = CountDownLatch(2)
+        val release = CountDownLatch(1)
+        val thirdEntered = CountDownLatch(1)
+
+        try {
+            repeat(2) {
+                executor.submit {
+                    pool.withReservation(1_000) {
+                        entered.countDown()
+                        release.await()
+                    }
+                }
+            }
+            assertTrue(entered.await(1, TimeUnit.SECONDS))
+
+            executor.submit {
+                pool.withReservation(1_000) {
+                    thirdEntered.countDown()
+                }
+            }
+            assertFalse("third reservation must wait while budget is full", thirdEntered.await(100, TimeUnit.MILLISECONDS))
+
+            release.countDown()
+            assertTrue("third reservation must proceed after release", thirdEntered.await(1, TimeUnit.SECONDS))
+        } finally {
+            release.countDown()
+            executor.shutdownNow()
+        }
+    }
+
+    @Test
+    fun `timed admission drops work instead of waiting indefinitely`() {
+        val pool = DecompressionResourcePool(
+            budgetBytes = 1_000,
+            unitBytes = 1_000,
+            waitTimeoutMs = 50
+        )
+        val entered = CountDownLatch(1)
+        val release = CountDownLatch(1)
+        val executor = Executors.newSingleThreadExecutor()
+
+        try {
+            executor.submit {
+                pool.withReservation(1_000) {
+                    entered.countDown()
+                    release.await()
+                }
+            }
+            assertTrue(entered.await(1, TimeUnit.SECONDS))
+            assertNull(pool.withReservation(1_000) { "unexpected" })
+        } finally {
+            release.countDown()
+            executor.shutdownNow()
+        }
+    }
+
+    @Test
+    fun `permits are released when decode throws`() {
+        val pool = DecompressionResourcePool(2_000, 1_000, 50)
+
+        try {
+            pool.withReservation(2_000) { error("boom") }
+        } catch (_: IllegalStateException) {
+            // Expected.
+        }
+
+        assertEquals(2, pool.availablePermits)
+        assertEquals("ok", pool.withReservation(2_000) { "ok" })
+    }
+
+    @Test
+    fun `runtime budget is based on heap memory and always admits one maximum packet`() {
+        val maxPacketResources = 20L * 1024 * 1024
+
+        assertEquals(
+            maxPacketResources,
+            DecompressionResourcePool.recommendedBudgetBytes(
+                maxHeapBytes = 64L * 1024 * 1024,
+                maxPacketResourceBytes = maxPacketResources
+            )
+        )
+        assertEquals(
+            32L * 1024 * 1024,
+            DecompressionResourcePool.recommendedBudgetBytes(
+                maxHeapBytes = 256L * 1024 * 1024,
+                maxPacketResourceBytes = maxPacketResources
+            )
+        )
+        assertEquals(
+            64L * 1024 * 1024,
+            DecompressionResourcePool.recommendedBudgetBytes(
+                maxHeapBytes = 2L * 1024 * 1024 * 1024,
+                maxPacketResourceBytes = maxPacketResources
+            )
+        )
+    }
+}

app/src/test/java/com/bitchat/android/ui/ChatUIUtilsTest.kt

@@ -14,6 +14,7 @@ import com.bitchat.android.ui.theme.LightBitchatColorScheme
 import com.bitchat.android.ui.theme.LightBitchatPalette
 import com.bitchat.android.ui.theme.MessageBodyTextStyle
 import com.bitchat.android.ui.theme.MessageSenderTextStyle
+import com.bitchat.android.ui.theme.PeerColorStyle
 import com.bitchat.android.ui.theme.colorForPeer
 import java.text.SimpleDateFormat
 import java.util.Date
@@ -444,8 +445,8 @@ class ChatUIUtilsTest {
 
     @Test
     fun `peer color hue is stable across light and dark, only chroma differs`() {
-        // Hue derivation must stay byte-identical to iOS; only saturation/value are tuned for
-        // the redesigned neutral message body.
+        // Hue derivation must stay byte-identical to iOS; only saturation/value are tuned per
+        // theme so dark mode stays muted-but-bright and light mode stays deep-but-readable.
         val identity = PeerIdentity.mesh("abc")
         val dark = colorForPeer(identity, DarkBitchatPalette)
         val light = colorForPeer(identity, LightBitchatPalette)
@@ -456,10 +457,16 @@ class ChatUIUtilsTest {
         rgbToHsv(light.red, light.green, light.blue, lightHsv)
 
         assertEquals(darkHsv[0].toDouble(), lightHsv[0].toDouble(), 1.0)
-        assertEquals(1.0, darkHsv[1].toDouble(), 0.01)
-        assertEquals(1.0, darkHsv[2].toDouble(), 0.01)
-        assertEquals(0.85, lightHsv[1].toDouble(), 0.01)
-        assertEquals(0.45, lightHsv[2].toDouble(), 0.01)
+        assertEquals(PeerColorStyle.Dark.saturation.toDouble(), darkHsv[1].toDouble(), 0.01)
+        assertEquals(PeerColorStyle.Dark.value.toDouble(), darkHsv[2].toDouble(), 0.01)
+        assertEquals(PeerColorStyle.Light.saturation.toDouble(), lightHsv[1].toDouble(), 0.01)
+        assertEquals(PeerColorStyle.Light.value.toDouble(), lightHsv[2].toDouble(), 0.01)
+        // Dark theme: muted chroma, never dark (readable on near-black).
+        assertTrue(darkHsv[1] < 0.75f)
+        assertTrue(darkHsv[2] >= 0.75f)
+        // Light theme: avoid neon / near-white peer labels.
+        assertTrue(lightHsv[1] < 0.85f)
+        assertTrue(lightHsv[2] <= 0.55f)
     }
 
     @Test
@@ -485,7 +492,7 @@ class ChatUIUtilsTest {
         assertEquals(Color(0xFFF5F5F5), DarkBitchatColorScheme.onSurface)
         assertTrue(LightBitchatColorScheme.onSurface != DarkBitchatColorScheme.onSurface)
         assertTrue(
-            LightBitchatPalette.peerColorValue != DarkBitchatPalette.peerColorValue
+            LightBitchatPalette.peerColors != DarkBitchatPalette.peerColors
         )
     }
 

app/src/test/kotlin/com/bitchat/FileTransferTest.kt

@@ -237,7 +237,7 @@ class FileTransferTest {
 
         // Given: Large file size (simulated)
         val largeFileSize = 100L * 1024 * 1024 // 100MB
-        val maxAllowedSize = 50L * 1024 * 1024 // 50MB
+        val maxAllowedSize = com.bitchat.android.util.AppConstants.Media.MAX_FILE_SIZE_BYTES
 
         // When: Checking if file can be transferred
         val isAllowed = largeFileSize <= maxAllowedSize

app/src/test/kotlin/com/bitchat/android/ui/MediaSendingManagerMigrationTest.kt

@@ -287,6 +287,43 @@ class MediaSendingManagerMigrationTest {
         assertTrue(messages.none { it.type == com.bitchat.android.model.BitchatMessageType.Image })
     }
 
+    @Test
+    fun `oversized file failure is posted to the private conversation and nothing is sent`() {
+        val bigFile = kotlin.io.path.createTempFile("oversized-private", ".jpg").toFile()
+        try {
+            bigFile.writeBytes(ByteArray(11 * 1024 * 1024) { 0x42 })
+
+            manager.sendImageNote(peerID, null, bigFile.absolutePath)
+
+            val messages = state.privateChats.value[peerID].orEmpty()
+            assertEquals(1, messages.size)
+            assertTrue(messages.single().content.contains("too large"))
+            assertTrue(messages.none { it.type == com.bitchat.android.model.BitchatMessageType.Image })
+            assertTrue(state.getMessagesValue().none { it.content.contains("too large") })
+            verify(mesh, never()).prepareFilePrivate(any(), any(), any(), any())
+        } finally {
+            bigFile.delete()
+        }
+    }
+
+    @Test
+    fun `oversized file failure is posted to the channel and nothing is sent`() {
+        val bigFile = kotlin.io.path.createTempFile("oversized-channel", ".jpg").toFile()
+        try {
+            bigFile.writeBytes(ByteArray(11 * 1024 * 1024) { 0x42 })
+
+            manager.sendImageNote(null, "#test", bigFile.absolutePath)
+
+            val channelMessages = state.getChannelMessagesValue()["#test"].orEmpty()
+            assertEquals(1, channelMessages.size)
+            assertTrue(channelMessages.single().content.contains("too large"))
+            assertTrue(state.getMessagesValue().none { it.content.contains("too large") })
+            verify(mesh, never()).prepareFilePrivate(any(), any(), any(), any())
+        } finally {
+            bigFile.delete()
+        }
+    }
+
     @Test
     fun `cancelled consent cannot later send or echo`() {
         whenever(mesh.prepareFilePrivate(eq(peerID), any(), any(), eq(false)))

app/src/test/kotlin/com/bitchat/android/ui/PrivateChatManagerTest.kt

@@ -107,6 +107,29 @@ class PrivateChatManagerTest {
         verify(meshService).sendReadReceipt(message.id, meshPeerID, "bob")
     }
 
+    @Test
+    fun `opening canonical unread conversation clears all source aliases`() {
+        val canonicalID = "contact_alice"
+        val nostrAlias = "nostr_0123456789abcdef"
+        val meshAlias = "0123456789abcdef"
+        val unrelatedConversation = "other-contact"
+        val meshService = mock<MeshService>()
+        state.setUnreadPrivateMessages(
+            setOf(canonicalID, nostrAlias, meshAlias, unrelatedConversation)
+        )
+
+        manager.startPrivateChat(
+            peerID = canonicalID,
+            meshService = meshService,
+            unreadAliases = setOf(canonicalID, nostrAlias, meshAlias)
+        )
+
+        assertEquals(
+            setOf(unrelatedConversation),
+            state.getUnreadPrivateMessagesValue()
+        )
+    }
+
     @Test
     fun `opening chat skips messages whose receipt send already completed`() {
         val noiseKey = ByteArray(32) { 8 }

app/src/test/kotlin/com/bitchat/android/ui/UnreadConversationSummaryTest.kt

@@ -0,0 +1,137 @@
+package com.bitchat.android.ui
+
+import com.bitchat.android.model.BitchatMessage
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.util.Date
+
+class UnreadConversationSummaryTest {
+    @Test
+    fun `unread conversations survive missing presence and sort by latest unread`() {
+        val older = incoming(
+            id = "older",
+            sender = "alice",
+            timestamp = 100
+        )
+        val newer = incoming(
+            id = "newer",
+            sender = "bob",
+            timestamp = 200
+        )
+
+        val rows = buildUnreadConversationSummaries(
+            unreadConversationIDs = setOf("alice-peer", "bob-peer"),
+            privateChats = mapOf(
+                "alice-peer" to listOf(older),
+                "bob-peer" to listOf(newer)
+            ),
+            currentUserIdentifiers = setOf("me"),
+            canonicalize = { it },
+            isMessageRead = { false }
+        )
+
+        assertEquals(listOf("bob-peer", "alice-peer"), rows.map { it.conversationID })
+        assertEquals(listOf("bob", "alice"), rows.map { it.displayName })
+    }
+
+    @Test
+    fun `canonical aliases produce one unread conversation row`() {
+        val message = incoming(
+            id = "message",
+            sender = "alice",
+            timestamp = 100
+        )
+
+        val rows = buildUnreadConversationSummaries(
+            unreadConversationIDs = setOf("mesh-alias", "nostr_alias"),
+            privateChats = mapOf(
+                "mesh-alias" to listOf(message),
+                "nostr_alias" to listOf(message)
+            ),
+            currentUserIdentifiers = setOf("me"),
+            canonicalize = { "contact_alice" },
+            isMessageRead = { false }
+        )
+
+        assertEquals(1, rows.size)
+        assertEquals("contact_alice", rows.single().conversationID)
+        assertEquals(DirectMessageTransport.NOSTR, rows.single().transport)
+        assertEquals(
+            setOf("mesh-alias", "nostr_alias", "contact_alice"),
+            rows.single().identityAliases
+        )
+    }
+
+    @Test
+    fun `only unseen incoming messages contribute to unread count`() {
+        val read = incoming(
+            id = "read",
+            sender = "alice",
+            timestamp = 100
+        )
+        val unread = incoming(
+            id = "unread",
+            sender = "alice",
+            timestamp = 200
+        )
+        val outgoing = incoming(
+            id = "outgoing",
+            sender = "me",
+            timestamp = 300
+        )
+
+        val row = buildUnreadConversationSummaries(
+            unreadConversationIDs = setOf("alice-peer"),
+            privateChats = mapOf("alice-peer" to listOf(read, unread, outgoing)),
+            currentUserIdentifiers = setOf("me"),
+            canonicalize = { it },
+            isMessageRead = { it.id == "read" }
+        ).single()
+
+        assertEquals(1, row.unreadCount)
+        assertEquals(200, row.latestMessageAt)
+    }
+
+    @Test
+    fun `unread key without hydrated messages still produces a row`() {
+        val row = buildUnreadConversationSummaries(
+            unreadConversationIDs = setOf("orphan-peer"),
+            privateChats = emptyMap(),
+            currentUserIdentifiers = setOf("me"),
+            canonicalize = { it },
+            isMessageRead = { false }
+        ).single()
+
+        assertEquals("orphan-peer", row.conversationID)
+        assertEquals(1, row.unreadCount)
+        assertTrue(row.displayName.isNotBlank())
+    }
+
+    @Test
+    fun `canonical unread lookup returns every matching source alias`() {
+        val aliases = matchingUnreadAliases(
+            unreadConversationIDs = setOf("mesh-alias", "nostr_alias", "other-contact"),
+            canonicalConversationID = "contact_alice",
+            canonicalize = { unreadID ->
+                if (unreadID == "other-contact") unreadID else "contact_alice"
+            }
+        )
+
+        assertEquals(
+            setOf("mesh-alias", "nostr_alias", "contact_alice"),
+            aliases
+        )
+    }
+
+    private fun incoming(
+        id: String,
+        sender: String,
+        timestamp: Long
+    ) = BitchatMessage(
+        id = id,
+        sender = sender,
+        content = "hello",
+        timestamp = Date(timestamp)
+    )
+}

docs/file_transfer.md

@@ -107,6 +107,28 @@ source-route metadata. It does not imply multi-gigabyte mesh transfer support.
   transport threshold; the data portion is at most 469 bytes and becomes
   smaller when recipient or source-route overhead is present.
 
+#### Compressed expansion rollout gate (resolved)
+
+Android's bounded decoder applies the same 10 MiB expanded-payload ceiling to every outer
+message type. It also requires a non-empty compressed body, an exact declared output size, and a
+complete deflate stream. The `FILE_TRANSFER (0x22)` byte cannot safely grant a larger ceiling: it is
+attacker-controlled before packet signature verification, and the current receive pipeline must
+inflate before it can perform that verification.
+
+New Android senders cap files just below 10 MiB (reserving envelope overhead) and refuse to encode
+any payload above the receiver ceiling; exceeding the cap surfaces a user-visible error in chat.
+Support for legacy >10 MiB compressed transfers is explicitly ended: legacy Android senders can
+still produce a highly compressible public file between 10 MiB and their 50 MiB UI limit that the
+bounded decoder rejects. Grandfathering 50 MiB is not safe after only a type check: inflation
+allocates the declared payload and
+`BitchatFilePacket.decode` currently copies the content again, creating a greater than 100 MiB peak
+for a maximum-size transfer.
+
+Before enabling that legacy range, receive processing needs an authenticated admission decision
+made before large allocation plus streaming inflation/TLV parsing into a bounded temporary file (or
+another ownership-preserving design that avoids the second full-size copy). The sender limit and a
+wire capability/version transition must then be coordinated so old and new clients fail predictably.
+
 ### 1.3 File Transfer TLV payload (BitchatFilePacket)
 
 The file payload is a TLV structure with mixed length field sizes to support large contents efficiently.