feat(run): stamp the drill's SDK build in the dry-run run-config [skip-docs]

The K8 drill captured a run-config that described the rig it rehearsed —
model ids, parameters, caps — without saying which SDK build would drive it.
The SDK's reported USD figure is computed against a price table frozen at build
time, so a rig record without the build is not traceable, and the drill exists
precisely to rig a future live run.

build_dry_run_config now takes the client the drill constructed and reads the
build from it, the same seam rule the provenance stamp follows: a drill driven
by the scripted stand-in stamps null rather than the installed version, because
reading the environment would describe a rig that never existed (§1).

Load-bearing (§11): the two new tests went RED before the change (no such key),
and the detach point is named in the class docstring — read importlib.metadata
instead of the client and the scripted drill claims a build it never used. The
existing dry-run tests assert individual keys rather than a key set, so the
additive field leaves them untouched, and byte-determinism still holds.

624 -> 627 passed, ruff + mypy --strict clean. README states the new field.
STATE post 2a, approved by the operator this session.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MQu2xxwedckjU56byu1aUG

README.md

@@ -116,8 +116,9 @@ description, never from its code)
   same orchestration with a scripted client; only the CLI's default constructs the SDK
   client. `--live-dry-run` is the **live-run drill** (K8): it builds everything a real run
   would (contracts → compose → client construction → preflight) and captures a `run_id`-named
-  `runconfig` + `preflight` pair to the outbox (model-id, parameters, caps — no wall-clock, so
-  the bytes stay deterministic), then **stops before the first model call**. It exits 0 when
+  `runconfig` + `preflight` pair to the outbox (model-id, parameters, caps, and the SDK build
+  read from the client the drill constructed — no wall-clock, so the bytes stay
+  deterministic), then **stops before the first model call**. It exits 0 when
   the preflight is clear and non-zero when it refused, but captures the artifacts and makes
   zero model calls either way — a future operator-gated live run is rigged and rehearsed
   offline, with no spend.

src/portfolio_optimiser_claude/run.py

@@ -443,6 +443,7 @@ def write_value_report(
 def build_dry_run_config(
     contracts: Contracts,
     *,
+    client: ModelClient,
     profile: str,
     bundle_name: str,
     run_id: str,
@@ -461,11 +462,18 @@ def build_dry_run_config(
     NO wall-clock date: the outbox promises byte-determinism (same input + run_id
     ⇒ identical file), and the run's date is stamped at report time (§4 pt 3),
     never into the deterministic log.
+
+    ``client`` is the client the drill CONSTRUCTED (never called): the rig's SDK
+    build is read from it, the same seam rule the provenance stamp follows. A
+    drill driven by the scripted stand-in used no SDK and stamps null — reading
+    the installed version from the environment would describe a rig that never
+    existed (§1).
     """
     return {
         "run_id": run_id,
         "profile": profile,
         "bundle": bundle_name,
+        "sdk_version": _client_sdk_version(client),
         "models": {
             role: resolve_model(contracts.model_map, role, profile=profile)
             for role in (_PROPOSER_ROLE, _CHECKER_ROLE)
@@ -793,6 +801,7 @@ def main(
         )
         run_config = build_dry_run_config(
             contracts,
+            client=client,
             profile=_DEFAULT_PROFILE,
             bundle_name=args.bundle.name,
             run_id=run_id,

tests/test_provenance_sdk_version_loadbearing.py

@@ -9,6 +9,10 @@ says which build produced it. But a run driven by the scripted stand-in used no
 SDK at all — stamping the installed version there would attribute a build to a
 run that never touched it, which is exactly the fabrication §1 forbids.
 
+The same rule governs the K8 drill's run-config: it records the build of the
+client the drill CONSTRUCTED (and never called), so the rehearsed rig is
+traceable without ever claiming a build the drill did not use.
+
 Detach proof: make the stamp read ``importlib.metadata`` instead of the client
 → a scripted run claims an SDK build it never used → red.
 
@@ -128,6 +132,70 @@ class TestTheStampStaysOptional:
             )
 
 
+class TestTheDrillStampsTheSameWay:
+    """LOAD-BEARING (§1, §11): the K8 drill's run-config obeys the same seam rule.
+
+    The run-config is the comparison protocol's §4 pt 3 record of what a live
+    run WOULD carry — model ids, parameters, caps. Without the build id it
+    describes a rig whose SDK version is unknown, which is the one thing that
+    makes a reported USD figure traceable. It is read from the CLIENT the drill
+    constructed, exactly like the provenance stamp: the drill builds the client
+    before it stops, so the honest source is right there.
+
+    Detach point: stamp ``importlib.metadata`` (or drop the client argument and
+    hard-code a value) → the scripted drill claims a build it never used → RED.
+    """
+
+    def _drill_runconfig(self, tmp_path: Path, *, sdk_version: str | None) -> dict[str, object]:
+        created: list[ScriptedClient] = []
+
+        def factory(contracts: Contracts, max_budget_usd_per_call: float) -> ModelClient:
+            # No replies: any model call would both record and raise, so the
+            # drill's zero-call promise still holds while this runs.
+            client = ScriptedClient(replies=[])
+            if sdk_version is not None:
+                client.sdk_version = sdk_version  # type: ignore[attr-defined]
+            created.append(client)
+            return client
+
+        outbox = tmp_path / "outbox"
+        main(
+            [
+                "--bundle",
+                str(BUNDLE),
+                "--outbox",
+                str(outbox),
+                "--run-id",
+                "drill-sdk",
+                "--live-dry-run",
+            ],
+            client_factory=factory,
+        )
+        (client,) = created
+        assert client.calls == []  # the drill still made no model call
+        payload: dict[str, object] = json.loads(
+            (outbox / "drill-sdk-runconfig.json").read_text(encoding="utf-8")
+        )
+        return payload
+
+    def test_a_drill_not_produced_by_the_sdk_stamps_no_build(self, tmp_path: Path) -> None:
+        payload = self._drill_runconfig(tmp_path, sdk_version=None)
+        assert payload["sdk_version"] is None
+        assert payload["sdk_version"] != importlib.metadata.version("claude-agent-sdk")
+
+    def test_the_drills_client_has_its_build_stamped_verbatim(self, tmp_path: Path) -> None:
+        payload = self._drill_runconfig(tmp_path, sdk_version=FIXTURE_BUILD)
+        assert payload["sdk_version"] == FIXTURE_BUILD
+
+    def test_the_stamp_does_not_disturb_the_rest_of_the_run_config(self, tmp_path: Path) -> None:
+        # The field is additive: §4 pt 3's existing content is unchanged, and the
+        # log still carries no wall-clock date (determinism).
+        payload = self._drill_runconfig(tmp_path, sdk_version=FIXTURE_BUILD)
+        assert payload["run_id"] == "drill-sdk"
+        assert payload["profile"] == "anthropic"
+        assert "date" not in payload
+
+
 class TestTheFasitIsNotRetroStamped:
     """LOAD-BEARING (§1): the historical record is never back-filled."""