feat: introduce reasoning pattern selection

tests/graph/question-formulator.test.js

@@ -3,6 +3,7 @@ import {
   assessUnknownAtomicity,
   formulateQuestion,
   formulateTieResolutionQuestion,
+  selectReasoningPattern,
   selectInvestigationStrategy,
 } from "@/lib/graph/question-formulator.js";
 import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";
@@ -105,6 +106,8 @@ describe("formulateQuestion", () => {
     const result = formulateQuestion({ node: unknown, graph });
 
     expect(result.strategy).toBe("decision_threshold");
+    expect(result.reasoningPattern).toBe("decision");
+    expect(result.questionFamily).toBe("decision_threshold");
     expect(result.question).toContain("What outcome");
     expect(result.question.toLowerCase()).toContain("justify");
   });
@@ -144,6 +147,8 @@ describe("formulateQuestion", () => {
     });
 
     expect(result.strategy).toBe("definition");
+    expect(result.reasoningPattern).toBe("definition");
+    expect(result.questionFamily).toBe("definition");
     expect(result.question).toMatch(/^What does /);
   });
 
@@ -213,9 +218,68 @@ describe("formulateQuestion", () => {
     });
 
     expect(result.strategy).toBe("contradiction_resolution");
+    expect(result.reasoningPattern).toBe("contradiction");
     expect(result.question).toContain("resolve the contradiction");
   });
 
+  it("reasoning pattern selection marks commercial validation as decision rather than explanation", () => {
+    const unknown = makeNode({
+      id: "n-commercial-pattern",
+      label:
+        "Whether the method addresses a genuine, high-priority problem for a specific audience",
+      description:
+        "Need to know whether this solves a real problem for a clear audience before continuing development.",
+      kind: "unknown",
+      status: "unknown",
+      confidence: "high",
+    });
+    const graph = makeGraphFor(unknown, {
+      centralStatement:
+        "Before investing more, we need to know whether continuing development is commercially justified.",
+    });
+
+    const result = selectReasoningPattern({ node: unknown, graph });
+
+    expect(result.pattern).toBe("decision");
+  });
+
+  it("comparison scenario selects the comparison pattern", () => {
+    const unknown = makeNode({
+      id: "n-comparison-pattern",
+      label: "How the two observations were measured",
+      description:
+        "Need evidence about the measure used for each observation, because that could help explain the difference.",
+      kind: "unknown",
+      status: "unknown",
+      confidence: "medium",
+    });
+    const graph = makeGraphFor(unknown, {
+      centralStatement: "Traffic increased, but sales stayed flat.",
+      nodes: [
+        makeNode({
+          id: "n-traffic-observation",
+          label: "Traffic increased.",
+          description: "Traffic increased.",
+          kind: "observation",
+          status: "supported",
+          confidence: "high",
+        }),
+        makeNode({
+          id: "n-sales-observation",
+          label: "Sales stayed flat.",
+          description: "Sales stayed flat.",
+          kind: "observation",
+          status: "supported",
+          confidence: "high",
+        }),
+      ],
+    });
+
+    const result = selectReasoningPattern({ node: unknown, graph });
+
+    expect(result.pattern).toBe("comparison");
+  });
+
   it("constraint unknown uses evidence-gathering within the fixed strategy set", () => {
     const unknown = makeNode({
       id: "n-constraint",
@@ -445,6 +509,7 @@ describe("formulateQuestion", () => {
       node: unknown,
       graph: makeGraphFor(unknown),
     });
+    expect(result.reasoningPattern).toBe("diagnosis");
     expect(result.strategy).toBeNull();
     expect(result.question).toBe(
       "What would clarify possible causes of the divergence in this situation?",