Structured output module

dify_agent.layers.output.output_layer declares Config, empty State and Capability. The reserved output name accepts a top-level object JSON Schema, optional description and strictness. The runner resolves native output_type before running the agent. A fresh dynamic type exposes the schema and performs JSON Schema validation in Pydantic AI's retry pipeline. The model-facing tool name is final_output. Local #/$defs/ references are supported; remote or recursive references are rejected before I/O. Resume resubmits current Config.