feat(v030): settings.sync_repo_url + sync_auto_enabled + sync_interval_min

- zod schema 확장: sync_repo_url (nullable), sync_auto_enabled (default true), sync_interval_min (int >= 5, default 30)
- getter/setter 6개 추가 (기존 ai_enabled / onboarding_completed 패턴)
- setSyncIntervalMin 은 non-integer / < 5 reject

tests/unit/SettingsService.test.ts

@@ -54,4 +54,40 @@ describe('SettingsService', () => {
     expect(existsSync(join(dir, 'settings.json.tmp'))).toBe(false);
     expect(existsSync(join(dir, 'settings.json'))).toBe(true);
   });
+
+  describe('v0.3.0 Cut E — sync settings', () => {
+    it('getSyncRepoUrl() defaults to null', async () => {
+      expect(await svc.getSyncRepoUrl()).toBeNull();
+    });
+
+    it('setSyncRepoUrl() / getSyncRepoUrl() round-trip', async () => {
+      await svc.setSyncRepoUrl('git@gitea.example:user/notes.git');
+      expect(await svc.getSyncRepoUrl()).toBe('git@gitea.example:user/notes.git');
+      // setting null clears
+      await svc.setSyncRepoUrl(null);
+      expect(await svc.getSyncRepoUrl()).toBeNull();
+    });
+
+    it('isAutoSyncEnabled() defaults to true', async () => {
+      expect(await svc.isAutoSyncEnabled()).toBe(true);
+    });
+
+    it('setAutoSyncEnabled() persists', async () => {
+      await svc.setAutoSyncEnabled(false);
+      expect(await svc.isAutoSyncEnabled()).toBe(false);
+      await svc.setAutoSyncEnabled(true);
+      expect(await svc.isAutoSyncEnabled()).toBe(true);
+    });
+
+    it('getSyncIntervalMin() defaults to 30', async () => {
+      expect(await svc.getSyncIntervalMin()).toBe(30);
+    });
+
+    it('setSyncIntervalMin() persists + rejects values < 5 / non-integer', async () => {
+      await svc.setSyncIntervalMin(15);
+      expect(await svc.getSyncIntervalMin()).toBe(15);
+      await expect(svc.setSyncIntervalMin(3)).rejects.toThrow();
+      await expect(svc.setSyncIntervalMin(10.5)).rejects.toThrow();
+    });
+  });
 });