merge: rebase canonical reveal flow onto main

frontend/angular/src/app/features/host/host-shell.component.spec.ts

@@ -340,5 +340,26 @@ describe('HostShellComponent gameplay wiring', () => {
     await component.refreshSession();
 
     expect(replaceState).toHaveBeenCalledWith(null, '', '#/host/guess/ABCD12');
+    expect(component.canStartRound).toBe(false);
+    expect(component.canShowQuestion).toBe(false);
+    expect(component.canMixAnswers).toBe(false);
+    expect(component.canCalculateScores).toBe(true);
+  });
+
+  it('uses phase_view_model to keep host action surface phase-specific', async () => {
+    const component = new HostShellComponent();
+
+    expect(component.canStartRound).toBe(true);
+    expect(component.canShowQuestion).toBe(false);
+
+    component.session = sessionDetailPayload('lie') as any;
+    expect(component.canStartRound).toBe(false);
+    expect(component.canShowQuestion).toBe(true);
+    expect(component.canMixAnswers).toBe(true);
+
+    component.session = sessionDetailPayload('reveal') as any;
+    expect(component.canRevealScoreboard).toBe(true);
+    expect(component.canStartNextRound).toBe(false);
+    expect(component.canFinishGame).toBe(false);
   });
 });