feat(api): expose the §5 provenance stamp on IngestResult

The stamp ({stem}@{sha256(raw)[:16]}) was computed internally but only
written into frontmatter, forcing consumers to recompute it from the
manifest bytes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/llm_ingestion_okf/materialize.py

@@ -42,9 +42,11 @@ _MANAGED_LINE_RE = re.compile(r"^- \[(?P<label>[^\]]*)\]\((?P<target>[^)]+)\)$")
 
 @dataclass(frozen=True)
 class IngestResult:
-    """The concept files written by one materialization run."""
+    """The concept files written by one materialization run, and the §5
+    provenance stamp (`{stem}@{sha256(raw)[:16]}`) they were stamped with."""
 
     written: tuple[Path, ...]
+    stamp: str
 
 
 def _render_frontmatter(frontmatter: dict[str, str]) -> str:
@@ -268,4 +270,4 @@ def materialize_bundle(
         _update_index_lines(index_path, owned - staged_names, labels_by_target)
     for extraction in manifest.extractions:
         _link_in_index(bundle, generated_filename(extraction.id), extraction.title)
-    return IngestResult(written=written)
+    return IngestResult(written=written, stamp=stamp)

tests/test_materialize.py

@@ -131,6 +131,16 @@ def test_result_lists_written_concept_files(file_setup: tuple[Path, Path]) -> No
     assert result.written == (bundle / "ingest-orders.md",)
 
 
+def test_result_exposes_manifest_stamp(file_setup: tuple[Path, Path]) -> None:
+    """The §5 provenance stamp ({stem}@{sha256(raw)[:16]}) is returned on the
+    result so consumers never have to recompute it from the manifest bytes."""
+    manifest_path, bundle = file_setup
+    result = materialize_bundle(manifest_path, bundle, INGESTED_AT)
+    assert result.stamp == stamp_of(manifest_path)
+    content = (bundle / "ingest-orders.md").read_text(encoding="utf-8")
+    assert f"ingest_manifest: {result.stamp}\n" in content
+
+
 def test_relative_root_resolves_against_manifest_dir(
     tmp_path: Path, file_setup: tuple[Path, Path], monkeypatch: pytest.MonkeyPatch
 ) -> None: