Sets up calendar package with core infrastructure

Adds core calendar package components including:
- Base services for events, resources, and settings
- Calendar app and orchestrator
- Build and bundling configuration
- IndexedDB storage setup

Prepares foundational architecture for calendar functionality

packages/calendar/src/extensions/customers/CustomerStore.ts

@@ -0,0 +1,17 @@
+import { IStore } from '../../storage/IStore';
+
+/**
+ * CustomerStore - IndexedDB ObjectStore definition for customers
+ */
+export class CustomerStore implements IStore {
+  static readonly STORE_NAME = 'customers';
+  readonly storeName = CustomerStore.STORE_NAME;
+
+  create(db: IDBDatabase): void {
+    const store = db.createObjectStore(CustomerStore.STORE_NAME, { keyPath: 'id' });
+
+    store.createIndex('name', 'name', { unique: false });
+    store.createIndex('phone', 'phone', { unique: false });
+    store.createIndex('syncStatus', 'syncStatus', { unique: false });
+  }
+}