feat: add automatic mode detection for Mollie payments

Automatically set Mollie payment mode to 'test' or 'live' based on
the API key prefix (test_ or live_). This ensures payments are
created in the correct mode and helps prevent configuration errors.

Changes:
- Add getMollieMode() helper to detect mode from API key
- Include mode parameter in payment creation
- Use type assertion for Mollie client compatibility

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

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@xtr-dev/payload-billing",
-  "version": "0.1.24",
+  "version": "0.1.25",
   "description": "PayloadCMS plugin for billing and payment provider integrations with tracking and local testing",
   "license": "MIT",
   "type": "module",

src/providers/mollie.ts

@@ -17,6 +17,13 @@ import { createContextLogger } from '../utils/logger'
 const symbol = Symbol.for('@xtr-dev/payload-billing/mollie')
 export type MollieProviderConfig = Parameters<typeof createMollieClient>[0]
 
+/**
+ * Determine the Mollie mode based on API key prefix
+ */
+function getMollieMode(apiKey: string): 'test' | 'live' {
+  return apiKey.startsWith('test_') ? 'test' : 'live'
+}
+
 /**
  * Type-safe mapping of Mollie payment status to internal status
  */
@@ -161,6 +168,9 @@ export const mollieProvider = (mollieConfig: MollieProviderConfig & {
       validateProductionUrl(redirectUrl, 'Redirect')
       validateProductionUrl(webhookUrl, 'Webhook')
 
+      // Determine mode from API key (test_ or live_)
+      const mode = getMollieMode(mollieConfig.apiKey)
+
       const molliePayment = await singleton.get(payload).payments.create({
         amount: {
           value: formatAmountForProvider(payment.amount, payment.currency),
@@ -169,7 +179,8 @@ export const mollieProvider = (mollieConfig: MollieProviderConfig & {
         description: payment.description || '',
         redirectUrl,
         webhookUrl,
-      });
+        mode,
+      } as any);
       payment.providerId = molliePayment.id
       // Use toPlainObject if available, otherwise spread the object (for compatibility with different Mollie client versions)
       payment.providerData = typeof molliePayment.toPlainObject === 'function'