feat(fase2): wire Step-1 ExpeL retrieval into the hypothesis prompt

Closes maalbilde §5 gap #1 (the one missing "feedback-into-prompt" dataflow)
for the OKF-bundle path. Before, ExpeL was computed AFTER generation into a
discarded SessionContext, so a prior verdict could not influence any hypothesis
(context_providers=0).

- New okf.py: framework-neutral OKF bundle navigation (index + frontmatter +
  cross-links), pure stdlib, no agent_framework/mcp (D7-portable), enforced by
  test_okf_is_maf_free.
- verdicts.py: seed_store_from_bundle + bundle_candidate_features build the
  ExpeL substrate + the pre-hypothesis query key from a bundle.
- run_project(bundle_dir=...): folds the candidate's prior verdicts into the
  generation context BEFORE generate_via_llm; the road path is unchanged.

Load-bearing (maalbilde §7): test_step1_expel_loadbearing proves a prior verdict
reaches the hypothesis prompt and goes RED when the fold is detached (shown via
TDD red->green). The marker is the minted verdict id (content hash) because
docs_dir==bundle_dir lets keyword chunk-stuffing leak the realization rate;
clean layer separation is Fase 2b.

Suite 121->133 passed; mypy + ruff check clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MHR8iKxJRxDiDfNw8HZmWE

tests/conftest.py

@@ -163,6 +163,43 @@ def make_portfolio_client_factory() -> Callable[..., Callable[[str], BaseChatCli
     return _make
 
 
+class _RecordingChatClient(SyntheticUsageChatClient):
+    """Records the incoming prompt blob per call into a SHARED sink, then returns a fixed valid
+    reply. Lets a test assert exactly what text reached the prompt — the probe the Step-1 ExpeL
+    wiring is made load-bearing against (does a prior verdict reach the hypothesis prompt?)."""
+
+    def __init__(self, sink: list[str], reply: str, *, tokens_per_reply: int = 8) -> None:
+        super().__init__(default_reply=reply, tokens_per_reply=tokens_per_reply)
+        self._sink = sink
+
+    def _inner_get_response(
+        self, *, messages: Sequence[Message], stream: bool, options: Any, **kwargs: Any
+    ) -> Any:
+        self._sink.append(" ".join(getattr(m, "text", "") or "" for m in messages))
+        return super()._inner_get_response(
+            messages=messages, stream=stream, options=options, **kwargs
+        )
+
+
+@pytest.fixture()
+def make_recording_client_factory() -> Callable[
+    [str], tuple[Callable[[str], BaseChatClient], list[str]]
+]:
+    """Return a maker that builds a per-role client factory recording every prompt blob into a
+    shared list. Returns ``(factory, recorded_prompts)`` so the test inspects what reached the
+    prompt across the whole run (debate rounds + generation)."""
+
+    def _make(reply: str) -> tuple[Callable[[str], BaseChatClient], list[str]]:
+        sink: list[str] = []
+
+        def factory(role: str) -> BaseChatClient:
+            return _RecordingChatClient(sink, reply)
+
+        return factory, sink
+
+    return _make
+
+
 @pytest.fixture()
 def fresh_store() -> VerdictStore:
     return VerdictStore(verdicts=[])