docs(clients): ReadBulk timeout is one shared deadline for the command, not per tag

Stream E made the worker wait once for all uncached tags. Fix the Go, Python, Rust, Java
and .NET library docs and CLI help text, the proto comment (default is the worker's
1000 ms), and the worker design doc. Regenerated Contracts Generated/ and the Java
generated protos; both diffs are comment-only.

clients/go/cmd/mxgw-go/main.go

@@ -571,7 +571,7 @@ func runReadBulk(ctx context.Context, args []string, stdout, stderr io.Writer) e
 	sessionID := flags.String("session-id", "", "gateway session id")
 	serverHandle := flags.Int("server-handle", 0, "MXAccess server handle")
 	items := flags.String("items", "", "comma-separated tag addresses")
-	timeoutMs := flags.Int("timeout-ms", 0, "per-tag snapshot timeout in milliseconds (0 = worker default)")
+	timeoutMs := flags.Int("timeout-ms", 0, "snapshot deadline in milliseconds, shared by all tags in the command (0 = worker default, 1000 ms)")
 
 	if err := flags.Parse(args); err != nil {
 		return err
@@ -754,7 +754,7 @@ func runBenchReadBulk(ctx context.Context, args []string, stdout, stderr io.Writ
 	tagStart := flags.Int("tag-start", 1, "first machine number")
 	tagPrefix := flags.String("tag-prefix", "TestMachine_", "tag prefix (machine number appended as %03d)")
 	tagAttribute := flags.String("tag-attribute", "TestChangingInt", "attribute appended to each tag prefix")
-	timeoutMs := flags.Int("timeout-ms", 1500, "per-tag snapshot timeout in milliseconds")
+	timeoutMs := flags.Int("timeout-ms", 1500, "snapshot deadline in milliseconds, shared by all tags in each ReadBulk command")
 
 	if err := flags.Parse(args); err != nil {
 		return err