Fix Swift 6 warning about unused result

- Add explicit discarding of removeValue results in NoiseSession
- Remove unnecessary _ = from BluetoothMeshService sync block
- Ensures clean builds with no warnings (except AppIntents metadata)

The warning was caused by Swift 6 being stricter about unused
results from methods that return values inside sync blocks.

bitchat/Noise/NoiseSession.swift

@@ -255,7 +255,7 @@ class NoiseSessionManager {
     
     func removeSession(for peerID: String) {
         managerQueue.sync(flags: .barrier) {
-            sessions.removeValue(forKey: peerID)
+            _ = sessions.removeValue(forKey: peerID)
         }
     }
     
@@ -265,7 +265,7 @@ class NoiseSessionManager {
             if let session = sessions[oldPeerID] {
                 // Move the session to the new peer ID
                 sessions[newPeerID] = session
-                sessions.removeValue(forKey: oldPeerID)
+                _ = sessions.removeValue(forKey: oldPeerID)
                 
                 SecurityLogger.log("Migrated Noise session from \(oldPeerID) to \(newPeerID)", category: SecurityLogger.noise, level: .info)
             }
@@ -290,7 +290,7 @@ class NoiseSessionManager {
             
             // Remove any existing non-established session
             if let existingSession = sessions[peerID], !existingSession.isEstablished() {
-                sessions.removeValue(forKey: peerID)
+                _ = sessions.removeValue(forKey: peerID)
             }
             
             // Create new initiator session
@@ -306,7 +306,7 @@ class NoiseSessionManager {
                 return handshakeData
             } catch {
                 // Clean up failed session
-                sessions.removeValue(forKey: peerID)
+                _ = sessions.removeValue(forKey: peerID)
                 throw error
             }
         }
@@ -328,7 +328,7 @@ class NoiseSessionManager {
                     // If we're in the middle of a handshake and receive a new initiation,
                     // reset and start fresh (the other side may have restarted)
                     if existing.getState() == .handshaking && message.count == 32 {
-                        sessions.removeValue(forKey: peerID)
+                        _ = sessions.removeValue(forKey: peerID)
                         shouldCreateNew = true
                     } else {
                         existingSession = existing
@@ -369,7 +369,7 @@ class NoiseSessionManager {
                 return response
             } catch {
                 // Reset the session on handshake failure so next attempt can start fresh
-                sessions.removeValue(forKey: peerID)
+                _ = sessions.removeValue(forKey: peerID)
                 
                 // Schedule callback outside the synchronized block to prevent deadlock
                 DispatchQueue.global().async { [weak self] in

bitchat/Services/BluetoothMeshService.swift

@@ -883,7 +883,7 @@ class BluetoothMeshService: NSObject {
     private func notifyPeerIDChange(oldPeerID: String, newPeerID: String, fingerprint: String) {
         DispatchQueue.main.async { [weak self] in
             // Remove old peer ID from active peers and announcedPeers
-            _ = self?.collectionsQueue.sync(flags: .barrier) {
+            self?.collectionsQueue.sync(flags: .barrier) {
                 self?.activePeers.remove(oldPeerID)
                 // Don't pre-insert the new peer ID - let the announce packet handle it
                 // This ensures the connect message logic works properly