3.86.0
(feat): Add opt-in allowUserAgentAppInfo config. When enabled, generated clients accept an
appInfo: { name, version?, comment? } option whose product token is appended to the
User-Agent header ({sdk}/{version} ... {product}/{product-version} ({comment})),
following RFC 9110. Disabled by default, so existing generated output is unchanged, and
it composes with includePlatformHeaders, the user-agent template config, and the
default {package}/{version} value. Caller-supplied values are token-encoded.