Optimize BLE mesh network for robustness and range (#314)

- Fixed relay probability calculation for 2-node networks (0% relay needed)
- Added protocol ACKs to prevent unnecessary retransmissions
- Implemented MessageState for enhanced duplicate detection
- Added exponential backoff for collision avoidance
- Fixed duplicate sends for bidirectional connections
- Resolved packet ID generation issues using immutable fields only
- Implemented smart rate limiting with progressive throttling
- Removed unnecessary debug logging and fixed build warnings
- Optimized message routing to prevent flooding in small networks

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchat/Protocols/BitchatProtocol.swift

@@ -139,8 +139,9 @@ struct BitchatPacket: Codable {
     let payload: Data
     let signature: Data?
     var ttl: UInt8
+    let sequenceNumber: UInt32  // New field for duplicate detection
     
-    init(type: UInt8, senderID: Data, recipientID: Data?, timestamp: UInt64, payload: Data, signature: Data?, ttl: UInt8) {
+    init(type: UInt8, senderID: Data, recipientID: Data?, timestamp: UInt64, payload: Data, signature: Data?, ttl: UInt8, sequenceNumber: UInt32 = 0) {
         self.version = 1
         self.type = type
         self.senderID = senderID
@@ -149,10 +150,11 @@ struct BitchatPacket: Codable {
         self.payload = payload
         self.signature = signature
         self.ttl = ttl
+        self.sequenceNumber = sequenceNumber
     }
     
     // Convenience initializer for new binary format
-    init(type: UInt8, ttl: UInt8, senderID: String, payload: Data) {
+    init(type: UInt8, ttl: UInt8, senderID: String, payload: Data, sequenceNumber: UInt32 = 0) {
         self.version = 1
         self.type = type
         // Convert hex string peer ID to binary data (8 bytes)
@@ -171,6 +173,7 @@ struct BitchatPacket: Codable {
         self.payload = payload
         self.signature = nil
         self.ttl = ttl
+        self.sequenceNumber = sequenceNumber
     }
     
     var data: Data? {