L3 Oral Tradition: PostgreSQL persistence layer for interpretations, minority opinions, teiku

Devarim 17:9 — v'darashta v'higidu lekha et d'var hamishpat.
The inquiry requires that what is found is RECORDED.

- Ecto Repo with graceful degradation (maybe_add_repo, like other engines)
- Migration: interpretations, minority_opinions, teiku_registry tables
  - Append-only enforcement via REVOKE UPDATE/DELETE
  - Includes eish_zarah fields: coupling_trace, grounding_type, challenge_sequence
- Ecto schemas: Interpretation, MinorityOpinion, TeikuRecord
  - Changeset validations: status inclusion, panel_size > 0, grounding_type enum
  - TeikuRecord.resolve_changeset restricts updates to resolved_at/resolution only
- L3.Store bridge module: record, query, count operations
- L3 tests tagged @moduletag :l3, excluded by default (no local PostgreSQL)
  - Enable with: SHORASHIM_L3=1 mix test --include l3
- All 76 existing Elixir tests pass, 195 Prolog tests pass, 33 Haskell tests pass

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

vav_pipeline/lib/vav_pipeline/repo.ex

@@ -0,0 +1,16 @@
+defmodule VavPipeline.Repo do
+  @moduledoc """
+  L3 — Oral Tradition. PostgreSQL repository.
+
+  Architecture §3.7: Append-only policy enforced at database level.
+  INSERT allowed. UPDATE and DELETE prohibited (via REVOKE on shorashim_app role).
+
+  The oral tradition is written once and never erased.
+  Luchot v'shivrei luchot munachim ba'aron — both the whole tablets
+  and the broken tablets are in the aron. What is recorded stays recorded.
+  """
+
+  use Ecto.Repo,
+    otp_app: :vav_pipeline,
+    adapter: Ecto.Adapters.Postgres
+end