feat(ingest): I3 — D7-speil av ingest (filkatalog/CSV), bygget fra commons-spec alene

Speiler MAF I2 fra shared/ingest-spec.md alene: manifest → CSV-konnektor →
materialisert OKF-bundle, byte-identisk med den delte golden-fasiten.

- ingest.py: ManifestContract (pydantic, fail-fast, file-kilde, verdict-reservasjon
  §3, id-grammatikk, max_rows), CSV-konnektor (boundary-checked fail-closed),
  materialisering (§5-frontmatter eksakt rekkefølge, markdown-tabell m/ escaping,
  LF-only, SHA-256 manifest-stamp), index-generering (§6), replacement §3/§5.
- okf.py: _parse_index_entry — tolererer frontmatterløs index (method-spec §3:
  index rendres via body = summary, ikke som typet concept-fil). Golden var
  spec-konform; D7-okf var strengere enn standarden. Scoped: non-index concept-
  filer krever fortsatt type (honesty-test).
- examples/ingest-golden-file/: repo-lokal golden (byte-frossen kopi av I2s fasit).
- Speiltester (I2s load-bearing-sett, alle detach-bevist røde): golden byte-fasit
  + mutasjonskontroller · provenance/navigability/verdict-reservasjon/re-ingest-safety
  · kontrakt fail-fast/max_rows/boundary/kollisjon · spec-integritet §11.
- docs/2026-07-04-I3-brief.md: brief + de to operatør-avgjorte beslutningene.

Suite 239 passed uten nøkkel/nettverk (189 + 50 nye) · ruff + mypy --strict rene.

[skip-docs] README + docs/extending.md er bevisst utsatt til I7 per sesjonsplan
(programmet batcher ingest-doc der, avgrenset til det D7 faktisk har — CSV nå,
SQL/HTTP senere). Endringen er dokumentert i docs/2026-07-04-I3-brief.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017MM6BWb1hWmJZuXFZ7rjxT

tests/test_okf.py

@@ -54,6 +54,32 @@ class TestNavigation:
         names = [c.path.name for c in navigate_bundle(bundle)]
         assert names == ["index.md", "b.md", "a.md"]
 
+    def test_frontmatterless_index_navigates(self, tmp_path: Path) -> None:
+        # method-spec §3 Step 1: the index contributes "the index body (the summary)"
+        # and is NOT a "non-index concept file" rendered as a `## {type}: {title}`
+        # section — so a generated index carrying only the summary + links (ingest
+        # spec §6 shape, frozen in the ingest golden) is valid. The index MAY omit
+        # frontmatter; okf must navigate it via its body, never raise.
+        _write(tmp_path / "index.md", "Summary line.\n- [A](a.md)\n")
+        _write(tmp_path / "a.md", "---\ntype: project\ntitle: A\n---\nBody A.")
+        concepts = navigate_bundle(tmp_path)
+        assert [c.path.name for c in concepts] == ["index.md", "a.md"]
+        index = concepts[0]
+        assert index.type == "index"  # default type, no KeyError for downstream .type reads
+        assert index.body == "Summary line.\n- [A](a.md)"  # body = the whole file
+        # The summary flows into the read-context as the leading section.
+        assert bundle_context(tmp_path).startswith("Summary line.")
+
+    def test_frontmatterless_tolerance_is_scoped_to_the_index(self, tmp_path: Path) -> None:
+        # LOAD-BEARING (honesty): the relaxation is for the index ENTRY POINT only.
+        # A NON-index concept file without frontmatter is still malformed and MUST
+        # raise — else the relaxation has silently weakened the `type`-required rule
+        # for concept files (method-spec §3 Step 1). RED if the tolerance leaks.
+        _write(tmp_path / "index.md", "Summary.\n- [A](a.md)\n")
+        _write(tmp_path / "a.md", "no frontmatter here\n")
+        with pytest.raises(ValueError, match="frontmatter"):
+            navigate_bundle(tmp_path)
+
     def test_out_of_bundle_and_escaping_targets_are_skipped(self, tmp_path: Path) -> None:
         # A target containing a path separator is out-of-bundle — skipped, never
         # raised; ../-escapes never resolve outside the bundle (fail-closed).