Write workspace debug artifacts during runs

docs/internal/pipeline.md

@@ -83,6 +83,11 @@ status, identity digest, dependency fingerprints, payload files, and payload
 digests validate for the current invocation. Missing or invalid checkpoints fall
 back to normal execution and are refreshed by the recorder.
 
+When workspace debug output is enabled, the CLI passes a debug recorder for the
+current run ID. The runner writes framework-boundary inputs, outputs,
+structured LLM calls, validator calls, timing, and retry attempt metadata
+through that interface. Concrete modules still do not receive workspace paths.
+
 ## Registries And Module Specs
 
 `pipeline.Registries` holds concrete constructors for execution. A