fix: resolve module resolution errors by replacing path aliases with relative imports

- Replace all @/ path aliases with proper relative imports and .js extensions
- Update @mollie/api-client peer dependency to support v4.x (^3.7.0 || ^4.0.0)
- Bump version to 0.1.5
- Ensure ESM compatibility for plugin distribution

Fixes module resolution error: "Cannot find package '@/collections'" when using
the plugin in external PayloadCMS projects.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/plugin/config.ts

@@ -1,6 +1,6 @@
 import { CollectionConfig } from 'payload'
-import { FieldsOverride } from '@/plugin/utils'
-import { PaymentProvider } from '@/plugin/types'
+import { FieldsOverride } from './utils.js'
+import { PaymentProvider } from './types/index.js'
 
 export const defaults = {
   paymentsCollection: 'payments',

src/plugin/index.ts

@@ -1,8 +1,8 @@
-import { createInvoicesCollection, createPaymentsCollection, createRefundsCollection } from '@/collections'
-import type { BillingPluginConfig } from '@/plugin/config'
+import { createInvoicesCollection, createPaymentsCollection, createRefundsCollection } from '../collections/index.js'
+import type { BillingPluginConfig } from './config.js'
 import type { Config, Payload } from 'payload'
-import { createSingleton } from '@/plugin/singleton'
-import type { PaymentProvider } from '@/providers'
+import { createSingleton } from './singleton.js'
+import type { PaymentProvider } from '../providers/index.js'
 
 const singleton = createSingleton(Symbol('billingPlugin'))
 

src/plugin/types/index.ts

@@ -1,5 +1,5 @@
-export * from './id'
-export * from './invoices'
-export * from './payments'
-export * from './refunds'
-export * from '../../providers/types'
+export * from './id.js'
+export * from './invoices.js'
+export * from './payments.js'
+export * from './refunds.js'
+export * from '../../providers/types.js'

src/plugin/types/invoices.ts

@@ -1,6 +1,5 @@
-import { Payment } from '@/plugin/types/payments'
-
-import { Id } from '@/plugin/types/id'
+import { Payment } from './payments.js'
+import { Id } from './id.js'
 
 export interface Invoice<TCustomer = unknown> {
   id: Id;

src/plugin/types/payments.ts

@@ -1,6 +1,6 @@
-import { Refund } from '@/plugin/types/refunds'
-import { Invoice } from '@/plugin/types/invoices'
-import { Id } from '@/plugin/types/id'
+import { Refund } from './refunds.js'
+import { Invoice } from './invoices.js'
+import { Id } from './id.js'
 
 export interface Payment {
   id: Id;

src/plugin/types/refunds.ts

@@ -1,4 +1,4 @@
-import { Payment } from '@/plugin/types/payments'
+import { Payment } from './payments.js'
 
 export interface Refund {
   id: number;

src/plugin/utils.ts

@@ -1,5 +1,5 @@
 import type { CollectionConfig, CollectionSlug, Field } from 'payload'
-import type { Id } from '@/plugin/types'
+import type { Id } from './types/index.js'
 
 export type FieldsOverride = (args: { defaultFields: Field[] }) => Field[]