refactor: group domain services into folders

tests/public-api.test.ts

@@ -10,6 +10,13 @@ import {
   type SpecialDateProvider,
   type TextModelAdapter,
 } from '../src';
+import { AvailabilityService } from '../src/availability';
+import { ConversationService } from '../src/conversation';
+import { FactDraftMemoryStore } from '../src/memory';
+import { PersonaService } from '../src/persona';
+import { GrokApiClient } from '../src/providers/grok';
+import { ScheduleService } from '../src/schedule';
+import { TimingProfile } from '../src/timing';
 
 describe('public API', () => {
   it('exports timing helpers and runtime availability constants', () => {
@@ -39,7 +46,7 @@ describe('public API', () => {
     expect(fact.topics.map((topic) => topic.name)).toEqual(['Mina', 'quiet cafés']);
   });
 
-  it('exports schedule, conversation, Grok, and external special-date adapter contracts', () => {
+  it('exports grouped service classes and provider runtime helpers', () => {
     const specialDateProvider: SpecialDateProvider = {
       async listSpecialDates() {
         return [{ date: '2026-05-08', title: 'Parents Day' }];
@@ -50,5 +57,13 @@ describe('public API', () => {
     expect(typeof replyToConversation).toBe('function');
     expect(typeof createGrokAdapters).toBe('function');
     expect(specialDateProvider.listSpecialDates).toBeTypeOf('function');
+
+    expect(AvailabilityService).toBeTypeOf('function');
+    expect(ConversationService).toBeTypeOf('function');
+    expect(FactDraftMemoryStore).toBeTypeOf('function');
+    expect(PersonaService).toBeTypeOf('function');
+    expect(GrokApiClient).toBeTypeOf('function');
+    expect(ScheduleService).toBeTypeOf('function');
+    expect(TimingProfile).toBeTypeOf('function');
   });
 });