fix: prevent phantom empty messages during sync

- Add content validation to skip empty or whitespace-only messages
- Apply validation in both channel and regular message handling
- Add validation at retry service level to prevent queuing empty messages
- This fixes the phantom space issue between synced messages

bitchat/Services/MessageRetryService.swift

@@ -61,6 +61,11 @@ class MessageRetryService {
         originalMessageID: String? = nil,
         originalTimestamp: Date? = nil
     ) {
+        // Don't queue empty or whitespace-only messages
+        guard !content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
+            return
+        }
+        
         // Don't queue if we're at capacity
         guard retryQueue.count < maxQueueSize else {
             return

bitchat/ViewModels/ChatViewModel.swift

@@ -2727,8 +2727,11 @@ extension ChatViewModel: BitchatDelegate {
                 
                 // Check if this is our own message being echoed back
                 if finalMessage.sender != nickname && finalMessage.sender != "system" {
+                    // Skip empty or whitespace-only messages
+                    if !finalMessage.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
                         channelMessages[channel]?.append(finalMessage)
                         channelMessages[channel]?.sort { $0.timestamp < $1.timestamp }
+                    }
                 } else if finalMessage.sender != "system" {
                     // Our own message - check if we already have it (by ID and content)
                     let messageExists = channelMessages[channel]?.contains { existingMsg in
@@ -2746,9 +2749,12 @@ extension ChatViewModel: BitchatDelegate {
                     } ?? false
                     if !messageExists {
                         // This is a message we sent from another device or it's missing locally
+                        // Skip empty or whitespace-only messages
+                        if !finalMessage.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
                             channelMessages[channel]?.append(finalMessage)
                             channelMessages[channel]?.sort { $0.timestamp < $1.timestamp }
                         }
+                    }
                 } else {
                     // System message - always add
                     channelMessages[channel]?.append(finalMessage)
@@ -2805,9 +2811,12 @@ extension ChatViewModel: BitchatDelegate {
             
             // Check if this is our own message being echoed back
             if finalMessage.sender != nickname && finalMessage.sender != "system" {
+                // Skip empty or whitespace-only messages
+                if !finalMessage.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
                     messages.append(finalMessage)
                     // Sort messages by timestamp to ensure proper ordering
                     messages.sort { $0.timestamp < $1.timestamp }
+                }
             } else if finalMessage.sender != "system" {
                 // Our own message - check if we already have it (by ID and content)
                 let messageExists = messages.contains { existingMsg in
@@ -2825,9 +2834,12 @@ extension ChatViewModel: BitchatDelegate {
                 }
                 if !messageExists {
                     // This is a message we sent from another device or it's missing locally
+                    // Skip empty or whitespace-only messages
+                    if !finalMessage.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
                         messages.append(finalMessage)
                         messages.sort { $0.timestamp < $1.timestamp }
                     }
+                }
             } else {
                 // System message - always add
                 messages.append(finalMessage)