Reconcile ordered pipeline documentation

docs/internal/state.md

@@ -35,13 +35,13 @@ they do not describe a current public state surface.
 Ordered-step lane checkpoints include the step identity in their storage scope.
 When a later lane consumes a generated artifact, its dependency fingerprints
 include the producer's artifact kind, complete schema identity, media type,
-canonical content digest, and size. A producer checkpoint may be decoded through
-the registered codec and handed off without rerunning it. Missing, rejected,
-corrupt, incompatible, or changed producer state produces a bounded
-`dependency_invalidated` decision for every transitive dependent lane; it does
-not permit stale downstream reuse. The CLI's selective recomputation policy
-records `forced_recompute` for the selected step and its dependents while
-requiring compatible predecessor checkpoints.
+canonical content digest, and size. Ordinary resume compares those fingerprints
+when progressively loading consumer stage checkpoints, so changed producer
+content produces `dependency_invalidated` rather than stale downstream reuse.
+Selective recomputation instead requires each unselected producer's accepted
+normalized artifact; invalid accepted state records its specific bounded reason
+and stops before the dependent. The selected step and its transitive dependents
+record `forced_recompute`.
 
 Ordinary resume loads extract, merge, and normalize checkpoints progressively
 and may execute later lane stages after an earlier cache miss. Selective
@@ -63,7 +63,8 @@ detail passes through one UTF-8-safe bounded sanitizer and contains only
 allowlisted diagnostic context, never payloads, references, credentials,
 environment values, or physical paths. Typed categories and codes remain intact
 through pipeline events and become strings only in manifest and debug-summary
-JSON.
+JSON. [Operations](../operations.md#resume-and-selective-recompute) is the
+canonical operator-facing reason-code reference.
 
 `internal/core/fileio` provides confined atomic file writes used by state
 collaborators. The chunk-plan store retains its stronger entry validation.
@@ -98,6 +99,8 @@ separately and never replace the command's primary error.
   terminalization, and output/report boundaries.
 - `internal/cli/state_hardening_test.go`: independent roots, reuse, failures,
   permissions, cleanup, and redaction.
+- `internal/cli/recompute_execution_contract_test.go`: selective recomputation,
+  filesystem recovery, deterministic decisions, and failed predecessor state.
 - `internal/cli/production_contract_test.go`: production composition and
   configuration validation at the CLI boundary.
 - `internal/cli/example_contract_test.go`: maintained example ownership.