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>

bitchatTests/EndToEnd/PrivateChatE2ETests.swift

@@ -365,7 +365,8 @@ final class PrivateChatE2ETests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: encrypted,
                         signature: packet.signature,
-                        ttl: packet.ttl
+                        ttl: packet.ttl,
+                        sequenceNumber: 1
                     )
                     self.bob.simulateIncomingPacket(encryptedPacket)
                 } catch {

bitchatTests/EndToEnd/PublicChatE2ETests.swift

@@ -122,7 +122,8 @@ final class PublicChatE2ETests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: relayPayload,
                         signature: packet.signature,
-                        ttl: packet.ttl - 1
+                        ttl: packet.ttl - 1,
+                        sequenceNumber: 1
                     )
                     
                     // Simulate relay to Charlie
@@ -450,7 +451,8 @@ final class PublicChatE2ETests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: relayPayload,
                         signature: packet.signature,
-                        ttl: packet.ttl - 1
+                        ttl: packet.ttl - 1,
+                        sequenceNumber: 1
                     )
                     
                     // Relay to next hops

bitchatTests/Integration/IntegrationTests.swift

@@ -197,7 +197,8 @@ final class IntegrationTests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: encrypted,
                         signature: packet.signature,
-                        ttl: packet.ttl
+                        ttl: packet.ttl,
+                        sequenceNumber: 1
                     )
                     self.nodes["Bob"]!.simulateIncomingPacket(encPacket)
                 }
@@ -698,7 +699,8 @@ final class IntegrationTests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: encrypted,
                         signature: packet.signature,
-                        ttl: packet.ttl
+                        ttl: packet.ttl,
+                        sequenceNumber: 1
                     )
                     self.nodes["Bob"]!.simulateIncomingPacket(encPacket)
                 }
@@ -805,7 +807,8 @@ final class IntegrationTests: XCTestCase {
                         timestamp: packet.timestamp,
                         payload: relayPayload,
                         signature: packet.signature,
-                        ttl: packet.ttl - 1
+                        ttl: packet.ttl - 1,
+                        sequenceNumber: 1
                     )
                     
                     for hop in nextHops {

bitchatTests/Mocks/MockBluetoothMeshService.swift

@@ -73,7 +73,8 @@ class MockBluetoothMeshService: BluetoothMeshService {
                 timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
                 payload: payload,
                 signature: nil,
-                ttl: 3
+                ttl: 3,
+                sequenceNumber: 1
             )
             
             sentMessages.append((message, packet))
@@ -111,7 +112,8 @@ class MockBluetoothMeshService: BluetoothMeshService {
                 timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
                 payload: payload,
                 signature: nil,
-                ttl: 3
+                ttl: 3,
+                sequenceNumber: 1
             )
             
             sentMessages.append((message, packet))

bitchatTests/TestUtilities/TestHelpers.swift

@@ -55,7 +55,8 @@ class TestHelpers {
         recipientID: String? = nil,
         payload: Data = "test payload".data(using: .utf8)!,
         signature: Data? = nil,
-        ttl: UInt8 = 3
+        ttl: UInt8 = 3,
+        sequenceNumber: UInt32 = 1
     ) -> BitchatPacket {
         return BitchatPacket(
             type: type,
@@ -64,7 +65,8 @@ class TestHelpers {
             timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
             payload: payload,
             signature: signature,
-            ttl: ttl
+            ttl: ttl,
+            sequenceNumber: sequenceNumber
         )
     }