Add a staged implementation plan for the initial framework and module composition architecture

docs/roadmap/2-framework-composition.md

@@ -32,65 +32,26 @@ Out of scope:
 - diagnostics run directory;
 - real D&D artifact schemas.
 
-## Proposed Stages
+## Target End State
 
-### Stage 1: Input Adapter Registry
+The repository should contain a minimal framework composition layer:
 
-Add a registry for `InputAdapter` constructors or instances.
+- `internal/framework/inputregistry` registers and builds input adapter
+  constructors by stable key.
+- `internal/framework/extractorregistry` registers and builds extractor
+  constructors by stable key.
+- `internal/framework/validators` provides shared validator decision helpers and
+  cardinality checks.
+- `internal/framework/runner` executes configured extractors against a
+  `SourceDocument`, applies validator chains, and returns approved and rejected
+  artifacts.
 
-The registry should:
+The runner should operate on already parsed source documents in this checkpoint.
+Raw input parsing and concrete input adapter behavior remain deferred to the
+Seriatim adapter checkpoint.
 
-- reject empty keys;
-- reject duplicate registrations;
-- return clear errors for unknown keys;
-- avoid importing concrete adapter packages from core contracts.
-
-### Stage 2: Extractor Registry
-
-Add a registry for extractor constructors or instances.
-
-The registry should:
-
-- support stable extractor keys;
-- support repeated extractor instances if needed later;
-- return clear errors for unknown keys;
-- avoid domain-specific logic.
-
-### Stage 3: Validator Decisions
-
-Add validator decision types and cardinality checks.
-
-Each validator should return exactly one decision for each candidate artifact it
-receives.
-
-Decision fields should include:
-
-- candidate index;
-- approved flag;
-- reason code;
-- message;
-- optional diagnostics path.
-
-### Stage 4: Minimal Runner
-
-Add a runner that can:
-
-1. receive a `SourceDocument`;
-2. execute configured extractors;
-3. validate candidate artifacts;
-4. return approved and rejected artifacts.
-
-Keep source chunking optional or stubbed at this checkpoint. The runner may
-operate on whole documents only until source-unit chunking is added later.
-
-### Stage 5: Runner Tests With Fakes
-
-Add tests with fake components that prove:
-
-- registered fake extractors run in configured order;
-- validators filter candidates deterministically;
-- decision cardinality failures are surfaced;
-- approved and rejected artifacts are returned in stable order.
+Implementation staging belongs in
+[`implementation.md`](implementation.md).
 
 ## Done Criteria