What
The SDK's URL stream transport can now be handed a callback to re-read authentication headers that went missing mid-connection. It is supplied only when CLAUDE_CODE_ENVIRONMENT_KIND is unset and a second condition is false, so it is absent inside bridge and other managed environments.
Evidence
rereadMissingAuthHeaders
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundleCLAUDE_CODE_ENVIRONMENT_KIND