Merge remote-tracking branch 'origin/feat/private-groups' into feat/integration-all

# Conflicts:
#	bitchat/Protocols/BitchatProtocol.swift
#	bitchat/Protocols/PeerCapabilities+Local.swift
#	bitchat/Services/BLE/BLEOutboundPacketPolicy.swift
#	bitchat/Services/BLE/BLEService.swift
#	bitchat/Services/Transport.swift
#	bitchat/Sync/GossipSyncManager.swift
#	bitchat/Sync/SyncTypeFlags.swift
#	bitchat/ViewModels/ChatTransportEventCoordinator.swift
#	bitchat/ViewModels/ChatViewModel.swift
#	bitchat/ViewModels/NostrInboundPipeline.swift
#	bitchatTests/ChatTransportEventCoordinatorContextTests.swift
#	bitchatTests/GossipSyncManagerTests.swift
#	localPackages/BitFoundation/Sources/BitFoundation/MessageType.swift

localPackages/BitFoundation/Sources/BitFoundation/MessageType.swift

@@ -25,9 +25,11 @@ public enum MessageType: UInt8 {
     case fragment = 0x20        // Single fragment type for large messages
     case fileTransfer = 0x22    // Binary file/audio/image payloads
 
-    // 0x23, 0x25-0x28 reserved for in-flight protocol work.
+    // 0x23/0x26-0x28 reserved by other in-flight features.
     case prekeyBundle = 0x24    // Signed batch of one-time prekeys (gossiped)
-    
+    case groupMessage = 0x25    // Group-encrypted broadcast (cleartext group ID, ChaChaPoly body)
+
+
     public var description: String {
         switch self {
         case .announce: return "announce"
@@ -40,6 +42,7 @@ public enum MessageType: UInt8 {
         case .fragment: return "fragment"
         case .fileTransfer: return "fileTransfer"
         case .prekeyBundle: return "prekeyBundle"
+        case .groupMessage: return "groupMessage"
         }
     }
 }

localPackages/BitFoundation/Sources/BitFoundation/PeerID.swift

@@ -34,6 +34,9 @@ public struct PeerID: Equatable, Hashable, Sendable {
         case geoDM = "nostr_"
         /// `"nostr:"` (+ 8 characters hex)
         case geoChat = "nostr:"
+        /// `"group_"` (+ 32 characters hex) — virtual conversation ID for a
+        /// private group (16-byte group ID). Never routed to a single peer.
+        case group = "group_"
     }
 
     public let prefix: Prefix
@@ -96,6 +99,22 @@ public extension PeerID {
     }
 }
 
+// MARK: - Group Conversation Helpers
+
+public extension PeerID {
+    /// Convenience init to create a virtual group conversation PeerID from a
+    /// 16-byte group ID ("group_" + 32 hex characters).
+    init(groupID: Data) {
+        self.init(str: Prefix.group.rawValue + groupID.hexEncodedString())
+    }
+
+    /// The 16-byte group ID behind a "group_" PeerID, if this is one.
+    var groupIDData: Data? {
+        guard isGroup, bare.count == 32 else { return nil }
+        return Data(hexString: bare)
+    }
+}
+
 // MARK: - Noise Public Key Helpers
 
 public extension PeerID {
@@ -143,6 +162,11 @@ public extension PeerID {
         prefix == .geoDM
     }
 
+    /// Returns true if `id` starts with "`group_`"
+    var isGroup: Bool {
+        prefix == .group
+    }
+
     func toPercentEncoded() -> String {
         id.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? id
     }