Add an initial staged implementation prompt fro the core contracts and skeleton

docs/roadmap/1-core-contracts-and-skeleton.md

@@ -32,79 +32,26 @@ Out of scope:
 - diagnostics run directory;
 - production config loading.
 
-## Proposed Stages
+## Target End State
 
-### Stage 1: Bootstrap Go Project
+The repository should contain a compileable Go application shell and stable core
+contract packages:
 
-Create:
+- `cmd/notarius` provides the executable entrypoint.
+- `internal/cli` provides a minimal CLI shell.
+- `internal/core/source` defines generic source documents, source units, source
+  references, and source validation helpers.
+- `internal/core/artifacts` defines extractor-neutral artifact candidate,
+  approved artifact, rejected artifact, and run manifest types.
+- `internal/framework/contracts` defines the adapter, extractor, validator, and
+  structured LLM interfaces used by later checkpoints.
 
-- `go.mod`;
-- `cmd/notarius/main.go`;
-- `internal/cli`;
-- a minimal CLI command surface that compiles.
+The contracts should be proven with fake implementations in tests. Those tests
+should demonstrate composition without real source adapters, real extractors,
+LLM provider calls, prompt assets, or diagnostics infrastructure.
 
-Expected validation:
-
-```sh
-go test ./...
-go build ./cmd/notarius
-```
-
-### Stage 2: Source Core Types
-
-Create `internal/core/source`.
-
-Initial types:
-
-- `SourceDocument`;
-- `SourceUnit`;
-- `SourceRef`;
-- source validation helpers for document ID, ordered units, unique unit IDs, and
-  non-empty text.
-
-Keep the model generic. Do not introduce transcript-specific field names into
-core source types.
-
-### Stage 3: Artifact Core Types
-
-Create `internal/core/artifacts`.
-
-Initial types:
-
-- artifact candidate;
-- approved artifact envelope;
-- rejected artifact record;
-- run manifest;
-- source-reference-bearing helper interfaces or conventions if useful.
-
-Keep the artifact model extractor-neutral. D&D-specific fields should wait until
-the D&D spells extractor checkpoint.
-
-### Stage 4: Framework Contract Types
-
-Create `internal/framework/contracts`.
-
-Initial contracts:
-
-- `InputAdapter`;
-- `Extractor`;
-- `Validator`;
-- structured LLM client interface placeholder;
-- parse, extraction, and validation request/response types.
-
-Interfaces should be small and should depend on core source/artifact types, not
-on concrete adapter or extractor packages.
-
-### Stage 5: Contract Tests With Fakes
-
-Add tests using fake adapter, extractor, and validator implementations.
-
-These tests should prove:
-
-- fake components can satisfy the interfaces;
-- source documents can flow into extraction requests;
-- artifact candidates can flow into validation requests;
-- the contracts are not forcing transcript or D&D assumptions.
+Implementation staging belongs in
+[`implementation.md`](implementation.md).
 
 ## Done Criteria