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