feat: add baseSystemPrompt

tests/persona.test.ts

@@ -29,6 +29,18 @@ describe('Persona initialization', () => {
     expect(debug).toContain('persona.initialized');
   });
 
+  it('exposes baseSystemPrompt on the persona instance when provided', async () => {
+    const memory = new InMemoryMemoryStore();
+    const persona = new Persona('Hana', 'Hana is a cheerful barista.', {
+      memory,
+      now: '2026-05-01T10:00:00.000Z',
+      baseSystemPrompt: 'You are a helpful assistant. Always be kind.',
+    });
+
+    await persona.ready();
+    expect(persona.baseSystemPrompt).toBe('You are a helpful assistant. Always be kind.');
+  });
+
   it('loads an existing persona space by space id without creating another space', async () => {
     const memory = new InMemoryMemoryStore();
     const created = new Persona('Joon', 'Joon is a freelance designer.', { memory, now: '2026-05-01T10:00:00.000Z' });