Add type-safe artifact lane resolution

docs/internal/overview.md

@@ -46,15 +46,19 @@ a sorted set of artifact lanes before the runner constructs any stage module.
 | `internal/framework/checkpoint` | Workspace-backed checkpoint loading, recording, and payload serialization. |
 | `internal/framework/debug` | Workspace-backed framework and LLM debug recording. |
 
-Framework contracts carry raw stage results between implementations. The
-runner owns handoff provenance, validation sequencing, rejection handling,
-checkpoint and debug boundaries, and final manifest assembly.
+Framework contracts provide both the production raw stage interfaces and typed
+artifact, provenance-wrapper, chunk-validator, serialized-validator, and
+typed-validator interfaces. The runner owns handoff provenance, validation
+sequencing, rejection handling, checkpoint and debug boundaries, and final
+manifest assembly.
 
-The artifact codec registry is an implemented foundation for heterogeneous
-typed artifacts. It validates codec metadata and schema identity and keeps
-exact Go-type checks behind framework-owned erased operations. Production
-module families do not register codecs yet, so pipeline resolution and
-execution continue to use the existing raw artifact contracts.
+Artifact registries support heterogeneous typed extraction entries and
+kind-specific merger, normalizer, and validator variants. Resolution derives a
+lane's kind from its extractor, requires the matching codec, verifies exact Go
+type equality across the lane, and records schema identity in the resolved lane
+and pipeline digest. Production module families do not register typed variants
+yet and continue through explicitly named legacy raw registrations. The current
+runner rejects a typed resolved lane instead of routing it through raw execution.
 
 ## Production Extensions