Integrate chunk validation retries

docs/internal/pipeline.md

@@ -162,6 +162,13 @@ settles the semantic policy immediately. Structural-output errors alone use the
 structural policy, and validation failure without rejection settles the
 validator-failure policy without regenerating the producer.
 
+Chunk planning uses this state machine for generated plans. A rejected
+automatic cache hit is not model material and therefore falls through to a
+fresh initial generation; it neither receives a correction nor overwrites the
+stored record. Only a newly generated, completely validated plan is published
+to the chunk-plan store. Rejected plans never advance, and validation-incomplete
+plans remain unpublishable.
+
 After terminal lane work, the runner assembles manifest provenance, normalized
 artifacts, rejections, warnings, and an optional accepted chunk map. When an
 output policy selected evidence lanes, it decodes accepted serialized normalize