remove username sniffer

PROTOCOL.md

@@ -195,7 +195,7 @@ Type : u8
 | `0x01` | Register       | C → S     | `Pattern: String` |
 | `0x02` | Unregister     | C → S     | `Pattern: String` |
 | `0x03` | RegisterAck    | S → C     | `Pattern: String`, `Status: u8` (0 = ok, 1 = invalid pattern) |
-| `0x04` | ControlRequest | S → C     | `CID: Bytes[16]`, `Pattern: String`, `PlayerIP: String`, `PlayerPort: U16`, `Username: String` |
+| `0x04` | ControlRequest | S → C     | `CID: Bytes[16]`, `Pattern: String`, `PlayerIP: String`, `PlayerPort: U16` |
 | `0x05` | Ping           | C → S     | `Nonce: I64` |
 | `0x06` | Pong           | S → C     | `Nonce: I64` |
 
@@ -214,9 +214,7 @@ Type : u8
   can look the pattern up in its own route table. `CID` is 16
   cryptographically-random bytes generated by the hub, unique to that pending
   player. `PlayerIP`/`PlayerPort` are the player's source address (used for
-  HAProxy v2). `Username` is the player's name, read best-effort from the Login
-  Start packet — present when the client pipelined it with the Handshake (the
-  usual case), otherwise an empty string. It is informational (logging) only.
+  HAProxy v2).
 * **Ping/Pong**: optional keepalive so idle control sessions survive NAT
   timeouts. The client pings periodically; the hub echoes the nonce.