Document feedback-aware validation retries

docs/internal/modules.md

@@ -22,6 +22,15 @@ to bindings whose declared execution class is `llm_backed` and rejects a
 binding-specific profile on a deterministic module. The user-facing precedence
 contract belongs in [Configuration](../config.md#pipelines).
 
+An eligible LLM-backed chunk, extract, merge, or normalize producer may also
+declare correction protocol `single_response_v1`. That declaration is a
+promise that the implementation accepts one attempt-local semantic correction
+and returns an owned copy of the exact one model response that directly
+controlled the candidate. It must forward correction only to its structured
+completion request; it must not manufacture prior-response material by
+serializing a normalized artifact or expose opaque application IDs. Input,
+output, validator, and deterministic specs cannot declare the protocol.
+
 Implementations that accept options must provide both an option validator and
 a builder. The validator is used while resolving configuration; the builder
 decodes the same options and constructs the implementation from the prepared
@@ -91,6 +100,12 @@ combined-material bound preserves the deterministic result under the family's
 fallback policy. Provider, transport, cancellation, and context-construction
 failures remain execution errors.
 
+When the engine actually makes a proposal call, its typed result carries the
+owned exact proposal response under the same correction contract as other
+eligible producers. Deterministic skip, limit, and fallback outcomes carry no
+model candidate, so a later rejection applies terminal policy without spending
+an ineffective semantic retry.
+
 The core supplies a conservative generic prompt and the single private
 response schema. A domain prompt may substitute its semantic instructions but
 mounts the core-owned protocol and candidate/transcript presentation assets.
@@ -111,6 +126,8 @@ its domain prompt.
 3. Implement strict option decoding, construction, and the typed stage
    interface. Preserve caller ownership: do not retain mutable request data
    and return defensive copies where an implementation exposes stored data.
+   If declaring correction capability, forward the request correction and
+   retain only the exact validated response that controlled the result.
 4. Register the module through its typed registry helper and add it to the
    owning family registrar. Add a default validator chain only when that
    family owns the behavior; otherwise require an explicit compatible chain.