Orphan UI chunks no longer crash on reconnect with negative index

Patch Changes

• 148babc: WorkflowChatTransport now drops orphan UI chunks (deltas/ends and tool output/approval chunks whose part was started before the resumed window) when reconnecting with a negative initialStartIndex, instead of crashing the AI SDK client. Self-contained tool-input-available/tool-input-error chunks establish the tool part and are never dropped. A one-time warning links to docs on rewinding to a step boundary server-side.
• e660e45: Reduce the doStreamStep step-boundary payload by returning minimal raw aggregates and reconstructing the StepResult outside the step, instead of serializing the full StepResult plus the per-chunk array into the durable event log.
• cc773bc: Expose totalUsage and finishReason on the WorkflowAgent.stream() result, mirroring GenerateTextResult/StreamTextResult and the existing onEnd event payload.
  • ai@7.0.17