feat: add BoxBrain persona runtime APIs

tests/public-api.test.ts

@@ -2,8 +2,11 @@ import { describe, expect, it } from 'vitest';
 import {
   createReplyDelay,
   createTypingDelay,
+  generateSchedule,
   ONLINE_AVAILABILITY,
+  replyToConversation,
   type BoxBrainFactDraft,
+  type SpecialDateProvider,
   type TextModelAdapter,
 } from '../src';
 
@@ -34,4 +37,16 @@ describe('public API', () => {
 
     expect(fact.topics.map((topic) => topic.name)).toEqual(['Mina', 'quiet cafés']);
   });
+
+  it('exports schedule, conversation, and external special-date adapter contracts', () => {
+    const specialDateProvider: SpecialDateProvider = {
+      async listSpecialDates() {
+        return [{ date: '2026-05-08', title: 'Parents Day' }];
+      },
+    };
+
+    expect(typeof generateSchedule).toBe('function');
+    expect(typeof replyToConversation).toBe('function');
+    expect(specialDateProvider.listSpecialDates).toBeTypeOf('function');
+  });
 });