fix(rectification): close round A/2 tail gaps in tests, CI, and stale-score reuse

Window_scan assertions now match the public from_sign/to_sign contract, the
staging quick gate runs the rectification Python suite, and compare-candidates
rescores when stored policy lags the live engine identity.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/tests/rectification-engine-convergence.test.ts

@@ -11,6 +11,10 @@ import {
 } from "../src/lib/rectification-agentic/core/snapshot-source.ts";
 import type { ConflictProbe } from "../src/lib/rectification-agentic/core/types.ts";
 import { contrastPacketFromLatestResult } from "../src/lib/rectification-agentic/v9/decision-from-dossier.ts";
+import {
+  cachedEngineScoreIsReusable,
+  liveEngineScoringIdentityFromEnv,
+} from "../src/lib/rectification-agentic/v9/engine-client.ts";
 import {
   parseDiscriminatingEventProbes,
   parseProspectiveProbes,
@@ -84,6 +88,39 @@ test("scoring policy version changes stale stored snapshots", () => {
   assert.equal(storedSnapshotIsCurrent(current, current), true);
 });
 
+test("matching fingerprints still rescore when stored policy lags the live engine", () => {
+  const fingerprints = {
+    evidenceLedgerFingerprint: "b".repeat(64),
+    candidateRangeFingerprint: "c".repeat(64),
+  };
+  const stored = {
+    ...fingerprints,
+    algorithmVersion: "rectification-v5-matrix-scoring-6",
+    policyVersion: "rectification-candidate-policy-v2",
+  };
+  assert.equal(
+    cachedEngineScoreIsReusable(stored, fingerprints, {
+      algorithmVersion: "rectification-v5-matrix-scoring-6",
+      policyVersion: "rectification-candidate-policy-v2",
+    }),
+    true,
+  );
+  assert.equal(
+    cachedEngineScoreIsReusable(stored, fingerprints, {
+      algorithmVersion: "rectification-v5-matrix-scoring-7",
+      policyVersion: "rectification-candidate-policy-v3",
+    }),
+    false,
+  );
+  const fromEnv = liveEngineScoringIdentityFromEnv({
+    RECTIFICATION_ENGINE_VERSION: "rectification-v5",
+    RECTIFICATION_DECISION_POLICY_VERSION: "rectification-candidate-policy-v3",
+  });
+  assert.equal(fromEnv.algorithmVersion, null);
+  assert.equal(fromEnv.policyVersion, "rectification-candidate-policy-v3");
+  assert.equal(cachedEngineScoreIsReusable(stored, fingerprints, fromEnv), false);
+});
+
 test("anchored known_event_quality distinguish probes stay in the public packet", () => {
   const parsed = parseDiscriminatingEventProbes([qualityProbe()]);
   assert.equal(parsed.length, 1);