feat: Refactor Medusa module and service patterns

.cursor/rules/medusa-development.mdc

@@ -38,23 +38,46 @@ You are an expert in Medusa v2, TypeScript, Node.js, PostgreSQL, and modern e-co
 // Module definition pattern
 import { Module } from "@medusajs/framework/utils"
 
-export const myModule = Module("my-module", {
+export const MY_MODULE = "my-module"
+
+export default Module(MY_MODULE, {
   service: MyService,
-  model: [MyModel],
 })
+```
 
-// Service pattern with dependency injection
+### Service Pattern with Dependency Injection
+```typescript
 import { MedusaService } from "@medusajs/framework/utils"
+import MyModel from "./models/my-model"
 
 class MyService extends MedusaService({
   MyModel,
 }) {
-  async create(data: CreateMyEntityInput): Promise<MyEntity> {
-    return await this.myModelRepository_.create(data)
+  // CRUD methods are automatically generated by MedusaService
+  // You can add custom methods here
+  async customMethod(data: CustomInput): Promise<CustomOutput> {
+    return await this.myModelRepository_.customQuery(data)
   }
 }
 ```
 
+### Module Registration
+```typescript
+// medusa-config.ts
+import { defineConfig } from "@medusajs/framework/utils"
+
+export default defineConfig({
+  projectConfig: {
+    // ... other config
+  },
+  modules: [
+    {
+      resolve: "./src/modules/my-module",
+    },
+  ],
+})
+```
+
 ### API Route Patterns
 ```typescript
 // Admin API route