test(confidence-engine): capture structural frontier priority regression

tests/graph/focused-investigation-boundaries.test.js

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import { makeNode, makeGraph } from "@/lib/graph/schema.js";
 import { formulateQuestionForTarget, buildFocusedDeconstructPrompt, validateFocusedDeconstructSchema } from "@/lib/graph/focused-investigation.js";
+import { FOCUSED_DECONSTRUCT_REGRESSION_CASES, validateRegressionFixtureIntegrity } from "./focused-deconstruct-regression-cases.mjs";
 
 // ── helpers ──────────────────────────────────────────────────────────────
 
@@ -230,3 +231,40 @@ describe("validateFocusedDeconstructSchema", () => {
     }
   });
 });
+
+// ── Regression fixture integrity (zero live calls) ──────────────────────────
+
+describe("FOCUSED_DECONSTRUCT_REGRESSION_CASES fixture integrity", () => {
+  it("has exactly 7 cases", () => {
+    expect(FOCUSED_DECONSTRUCT_REGRESSION_CASES.length).toBe(7);
+  });
+
+  it("all IDs are unique", () => {
+    const ids = FOCUSED_DECONSTRUCT_REGRESSION_CASES.map((c) => c.id);
+    expect(new Set(ids).size).toBe(ids.length);
+  });
+
+  it("contains the new structural-frontier case ID", () => {
+    const ids = FOCUSED_DECONSTRUCT_REGRESSION_CASES.map((c) => c.id);
+    expect(ids).toContain("structural-frontier-over-working-example-detail");
+  });
+
+  it("preserves all six original case IDs", () => {
+    const ids = FOCUSED_DECONSTRUCT_REGRESSION_CASES.map((c) => c.id);
+    for (const origId of [
+      "nearest-frontier-wins",
+      "no-genuine-assumption",
+      "genuine-evidence-sufficiency-assumption",
+      "juxtaposition-must-not-create-link",
+      "tentative-observation-fidelity",
+      "genuine-dependency-frontier",
+    ]) {
+      expect(ids).toContain(origId);
+    }
+  });
+
+  it("validateRegressionFixtureIntegrity reports zero errors", () => {
+    const errors = validateRegressionFixtureIntegrity();
+    expect(errors).toEqual([]);
+  });
+});