reasoning: use structured semantic fidelity contract

tests/graph/update-proposal.test.js

@@ -104,7 +104,7 @@ describe("parseGraphUpdateProposal", () => {
     expect(result.proposal.addedNodes[0].id).toBe("n-new");
   });
 
-  it("accepts live-style free-text answerMeaning hints without requiring enum tokens", () => {
+  it("rejects supportCategory values outside the existing enum", () => {
     const result = parseGraphUpdateProposal({
       ...makeValidProposal(),
       answerMeaning: {
@@ -118,15 +118,10 @@ describe("parseGraphUpdateProposal", () => {
       },
     });
 
-    expect(result.success).toBe(true);
-    expect(result.proposal.answerMeaning).toMatchObject({
-      supportCategory: "conditional_preference",
-      resolutionGuidance:
-        "Identify and quantify the threshold conditions that trigger risk acceptance.",
-    });
+    expect(result.success).toBe(false);
   });
 
-  it("accepts the earlier live Regression B wording variant without special aliasing", () => {
+  it("rejects the earlier live Regression B wording variant when it is outside the existing enum", () => {
     const result = parseGraphUpdateProposal({
       ...makeValidProposal(),
       answerMeaning: {
@@ -139,10 +134,26 @@ describe("parseGraphUpdateProposal", () => {
       },
     });
 
+    expect(result.success).toBe(false);
+  });
+
+  it("accepts valid structured answerMeaning enum values", () => {
+    const result = parseGraphUpdateProposal({
+      ...makeValidProposal(),
+      answerMeaning: {
+        userSupportedMeaning:
+          "I'd normally avoid more risk, but for the right opportunity I might accept some.",
+        possibleInference:
+          "This may support later clarification, but the condition remains material.",
+        supportCategory: "conditional_tradeoff",
+        resolutionGuidance: "may_resolve",
+      },
+    });
+
     expect(result.success).toBe(true);
     expect(result.proposal.answerMeaning).toMatchObject({
-      supportCategory: "conditional_qualification",
-      resolutionGuidance: "may resolve once the condition is clarified",
+      supportCategory: "conditional_tradeoff",
+      resolutionGuidance: "may_resolve",
     });
   });
 
@@ -289,7 +300,7 @@ describe("parseGraphUpdateProposal", () => {
     expect(result.success).toBe(false);
   });
 
-  it("does not reject unsupported free-text answerMeaning labels at parse time", () => {
+  it("rejects unsupported answerMeaning enum labels at parse time", () => {
     const result = parseGraphUpdateProposal({
       ...makeValidProposal(),
       answerMeaning: {
@@ -300,11 +311,7 @@ describe("parseGraphUpdateProposal", () => {
       },
     });
 
-    expect(result.success).toBe(true);
-    expect(result.proposal.answerMeaning).toMatchObject({
-      supportCategory: "constraint_preference_mix",
-      resolutionGuidance: "needs more nuance",
-    });
+    expect(result.success).toBe(false);
   });
 
   it("defaults missing selectedQuestion to null", () => {