Add idiomatic documentation to Go, Java, Python, and Rust clients

clients/go/mxgateway/client.go

@@ -1,3 +1,14 @@
+// Package mxgateway is the Go client for the MXAccess Gateway gRPC service.
+//
+// The package wraps the generated gRPC contract with session-oriented helpers
+// for invoking MXAccess commands, streaming events, and browsing the Galaxy
+// Repository. Authentication uses an API-key bearer token attached as gRPC
+// metadata on every call.
+//
+// Typical use opens a Client with Dial, opens a Session, invokes commands such
+// as Register, AddItem, Advise, and Write, and consumes events via
+// SubscribeEvents. Galaxy Repository browse RPCs are exposed through
+// GalaxyClient.
 package mxgateway
 
 import (
@@ -219,10 +230,15 @@ func resolveTransportCredentials(opts Options) (credentials.TransportCredentials
 
 // OpenSessionOptions describes fields used to create an OpenSessionRequest.
 type OpenSessionOptions struct {
-	RequestedBackend    string
-	ClientSessionName   string
+	// RequestedBackend selects the gateway worker backend (empty for default).
+	RequestedBackend string
+	// ClientSessionName is a human-readable name recorded on the session.
+	ClientSessionName string
+	// ClientCorrelationID echoes through gateway logs and replies for tracing.
 	ClientCorrelationID string
-	CommandTimeout      time.Duration
+	// CommandTimeout sets the per-command timeout the gateway forwards to the
+	// worker; zero leaves the gateway default in place.
+	CommandTimeout time.Duration
 }
 
 // Request returns the raw protobuf OpenSessionRequest for these options.