feat: setup gesture agent and adjust command port for the UI

ref: N25B-334

src/control_backend/schemas/ri_message.py

@@ -10,6 +10,7 @@ class RIEndpoint(str, Enum):
     """
 
     SPEECH = "actuate/speech"
+    GESTURE = "actuate/gesture"
     PING = "ping"
     NEGOTIATE_PORTS = "negotiate/ports"
 
@@ -36,3 +37,15 @@ class SpeechCommand(RIMessage):
 
     endpoint: RIEndpoint = RIEndpoint(RIEndpoint.SPEECH)
     data: str
+
+
+class GestureCommand(RIMessage):
+    """
+    A specific command to make the robot do a gesture.
+
+    :ivar endpoint: Fixed to ``RIEndpoint.GESTURE``.
+    :ivar data: The id of the gesture to be executed.
+    """
+
+    endpoint: RIEndpoint = RIEndpoint(RIEndpoint.SPEECH)
+    data: str