fix: harden dynamic rectification protocol

frontend/tests/birth-time-dynamic-choice.test.ts

@@ -4,6 +4,7 @@ import { join } from "node:path";
 import test from "node:test";
 import { publicDynamicChoiceQuestionSchema } from "../src/lib/birth-time-dynamic-choice.ts";
 import { persistedDynamicChoiceQuestionSchema } from "../src/lib/birth-time-dynamic-choice-internal.ts";
+import { dynamicJourneyTurnStateSchema, journeyTurnStateSchema } from "../src/lib/birth-time-journey-turn-protocol.ts";
 
 const internalQuestion = {
   questionId: "11111111-1111-4111-8111-111111111111",
@@ -133,3 +134,42 @@ test("public code never imports the internal dynamic choice contract", () => {
     assert.equal(readFileSync(path, "utf8").includes("birth-time-dynamic-choice-internal"), false, path);
   }
 });
+
+test("dynamic turn state is explicitly discriminated from the legacy protocol", () => {
+  const dynamicTurn = {
+    journeyProtocol: "dynamic-choice-v2",
+    turnVersion: 0,
+    nextAction: { kind: "generate_dynamic_question" },
+    progress: {
+      phase: "question",
+      answeredCount: 0,
+      effectiveAnswerCount: 0,
+      currentRange: { startTime: "09:00", endTime: "10:00" },
+      previousRange: null,
+      plateauCount: 0,
+    },
+    permissions: { canConfirmCandidate: false },
+  };
+
+  assert.equal(dynamicJourneyTurnStateSchema.safeParse(dynamicTurn).success, true);
+  assert.equal(journeyTurnStateSchema.safeParse(dynamicTurn).success, false);
+  assert.equal(dynamicJourneyTurnStateSchema.safeParse({
+    ...dynamicTurn,
+    journeyProtocol: "legacy-guided-v1",
+  }).success, false);
+  assert.equal(dynamicJourneyTurnStateSchema.safeParse({
+    ...dynamicTurn,
+    nextAction: {
+      kind: "ask_baseline_evidence",
+      question: {
+        questionId: "legacy",
+        phase: "baseline",
+        domain: "career",
+        requestedPrecision: ["year"],
+        allowUnknown: true,
+        purposeCode: "candidate_difference_career",
+        plannerVersion: "candidate-difference-v1",
+      },
+    },
+  }).success, false);
+});

frontend/tests/birth-time-dynamic-stop-policy.test.ts

@@ -34,6 +34,7 @@ function decisionFor(overrides: Partial<Parameters<typeof decideDynamicStop>[0]>
     usefulOpportunityCount: 1,
     repeatedOnly: false,
     effectiveAnswerCount: 1,
+    forcedReason: null,
     ...overrides,
   });
 }
@@ -53,6 +54,7 @@ test("two effective unchanged scores stop without starting another question", ()
     usefulOpportunityCount: 3,
     repeatedOnly: false,
     effectiveAnswerCount: 6,
+    forcedReason: null,
   });
 
   assert.deepEqual(decision, { kind: "finish", reason: "plateau", plateauCount: 2 });
@@ -67,12 +69,15 @@ test("unknown answers do not advance plateau or the effective safety count", ()
     usefulOpportunityCount: 2,
     repeatedOnly: false,
     effectiveAnswerCount: 4,
+    forcedReason: null,
   });
 
   assert.deepEqual(decision, { kind: "continue", plateauCount: 1 });
 });
 
 test("terminal conditions are deterministic", () => {
+  assert.equal(finishReason({ result: null, forcedReason: "user_finished" }), "user_finished");
+  assert.equal(finishReason({ result: null, forcedReason: "generation_unavailable" }), "generation_unavailable");
   assert.equal(finishReason({ result: { ...lowCandidate, confidence: "high", canApply: true, winningSegment: {
     startTime: "09:00", endTime: "09:05", representativeTime: "09:03", widthMinutes: 5,
   }, eventCount: 4, domainCount: 3, marginPercent: 20 } }), "high_confidence");
@@ -81,6 +86,15 @@ test("terminal conditions are deterministic", () => {
   assert.equal(finishReason({ effectiveAnswerCount: 10 }), "safety_cap");
 });
 
+test("forced terminal reasons win over a high-confidence score", () => {
+  assert.equal(finishReason({
+    result: { ...lowCandidate, confidence: "high", canApply: true, winningSegment: {
+      startTime: "09:00", endTime: "09:05", representativeTime: "09:03", widthMinutes: 5,
+    }, eventCount: 4, domainCount: 3, marginPercent: 20 },
+    forcedReason: "user_finished",
+  }), "user_finished");
+});
+
 test("a two point margin change resets the plateau", () => {
   const decision = decisionFor({
     result: { ...mediumCandidate, marginPercent: 17 },