fix: restore signs after navigation

tests/unit/sign-controller.test.ts

@@ -458,4 +458,30 @@ describe('clock-driven sign lifecycle', () => {
       candidateId: 'experience',
     }))).toBeNull();
   });
+
+  it('starts a fresh passive sign traversal after explicit navigation', () => {
+    const controller = createSignController();
+    controller.sample(sample());
+    controller.sample(sample({ now: 1_200, direction: 0, deltaY: 0 }));
+    controller.sample(sample({ now: 2_600, direction: 0, deltaY: 0 }));
+    controller.sample(sample({ now: 3_300, direction: 0, deltaY: 0 }));
+
+    expect(controller.sample(sample({
+      now: 3_400,
+      source: 'explicit-navigation',
+      activeSectionId: 'contact',
+      candidateId: null,
+      candidateDistanceVh: null,
+    }))).toBeNull();
+    expect(controller.sample(sample({
+      now: 3_500,
+      source: 'explicit-navigation',
+      activeSectionId: 'start',
+    }))).toBeNull();
+
+    expect(controller.sample(sample({ now: 3_600 }))).toMatchObject({
+      targetId: 'profile',
+      phase: 'anticipate',
+    });
+  });
 });