Add a framework mechanism for prepared modules and validators to contribute checkpoint identity fingerprints

docs/internal/modules.md

@@ -158,7 +158,12 @@ reference into an immutable effective catalog and adds a generated
 canonical-name-only JSON input to every structured completion request. Overlay
 failures therefore stop construction before source parsing or an LLM call;
 campaign references remain separate disambiguation inputs and never become
-source evidence. The separate `internal/modules/dnd/codec/spells` package
+source evidence. Both the extractor and deterministic catalog validator expose
+the effective base-plus-overlay semantic digest as scoped prepared-component
+checkpoint identity. Raw overlay provenance independently covers file-byte
+changes, while the semantic digest also invalidates reuse when the embedded
+catalog or catalog composition changes. The separate
+`internal/modules/dnd/codec/spells` package
 owns the durable schema and stable JSON representation for artifact kind
 `dnd/spell-list`. The runner keeps the result typed through validators and later
 stages, using the codec only for checkpoint, debug, and output boundaries.

docs/internal/pipeline.md

@@ -126,8 +126,16 @@ then output. It stops at the first error with pipeline, stage, lane, module, and
 validator context as applicable. It never invokes an operation method.
 
 `PreparedPipeline` keeps private constructed executors and exposes cloned
-resolved input, chunk, lane, and output identities. `pipeline.RunInput` carries
-that prepared pipeline, raw source input, run identity and timing, optional
+resolved input, chunk, lane, and output identities. Prepared components may
+implement `pipeline.CheckpointFingerprintProvider` to contribute explicit
+semantic identities to checkpoint reuse. Preparation trims and validates each
+non-secret name and value, prefixes it with the component's stage, lane,
+module, and validator scope, rejects duplicates, and retains the resulting
+sorted collection behind a defensive-copy accessor. Fingerprints must be
+stable and must not contain source content, credentials, local paths,
+timestamps, or other invocation-specific values.
+
+`pipeline.RunInput` carries that prepared pipeline, raw source input, run identity and timing, optional
 session and profile metadata, a chunk-plan store and mode, and checkpoint/debug
 collaborators. The runner
 parses source bytes through the already constructed input adapter. Later stage
@@ -267,6 +275,14 @@ bytes, and decode failures become explicit reuse misses and execute the step
 normally. Dependency fingerprints and debug content digests use the same stable
 codec bytes that cross those boundaries.
 
+The CLI includes prepared-component fingerprints in the run-wide checkpoint
+identity alongside resolved configuration, raw input, reference provenance,
+runtime overrides, and LLM-profile fingerprints. Module metadata is not used
+implicitly for cache identity: components opt in only with stable semantic
+values that can change accepted output. Adding or changing a component
+fingerprint intentionally produces a cold cache miss. Existing checkpoint
+schemas and paths remain unchanged.
+
 Debug instrumentation wraps run, stage, attempt, validator, and structured LLM
 boundaries. Every executed chunk, extract, merge, and normalize attempt writes
 one terminal envelope for acceptance, validator rejection, module or validator

docs/internal/state.md

@@ -25,6 +25,9 @@ not `bypass`.
 `internal/framework/checkpoint` owns checkpoint identity, manifests, payload
 codecs, loader, and recorder. The CLI constructs a recorder whenever checkpoint
 recording is enabled and constructs a loader only for a `--resume` invocation.
+Identity incorporates explicit stable semantic fingerprints collected from
+prepared modules and validators in addition to configuration, input,
+references, runtime overrides, and LLM profiles.
 The serialized
 `workspace_schema_version` identifiers are frozen wire-compatibility fields;
 they do not describe a current public state surface.