refactor: centralize visible phase mapping

src/types.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from 'vitest';
+
+import { normalizeAgentOutputPhase, toVisiblePhase } from './types.js';
+
+describe('phase helpers', () => {
+  it('maps agent output phases to visible phases', () => {
+    expect(toVisiblePhase('intermediate')).toBe('silent');
+    expect(toVisiblePhase('tool-activity')).toBe('silent');
+    expect(toVisiblePhase('progress')).toBe('progress');
+    expect(toVisiblePhase('final')).toBe('final');
+  });
+
+  it('normalizes missing agent output phases to final', () => {
+    expect(normalizeAgentOutputPhase(undefined)).toBe('final');
+    expect(normalizeAgentOutputPhase('progress')).toBe('progress');
+  });
+});