Migrate PaymentMonitorService to dependency injection pattern

- Convert PaymentMonitorService to extend BaseService with proper metadata
- Add invoiceService property to BaseService for payment status checking
- Register PaymentMonitorService in market module with DI container
- Update market store to use injected service instead of singleton import
- Remove exported singleton instance from service file
- Add proper service initialization and cleanup in market module

This completes the third legacy service migration, following InvoiceService
and NostrmarketService. The service now properly integrates with the DI
architecture for better testing, lifecycle management, and loose coupling.

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

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

src/modules/market/index.ts

@@ -19,6 +19,7 @@ import { useMarketPreloader } from './composables/useMarketPreloader'
 
 // Import services
 import { NostrmarketService } from './services/nostrmarketService'
+import { PaymentMonitorService } from './services/paymentMonitor'
 
 export interface MarketModuleConfig {
   defaultCurrency: string
@@ -44,11 +45,14 @@ export const marketModule: ModulePlugin = {
       throw new Error('Market module requires configuration')
     }
 
-    // Create and register NostrmarketService instance
+    // Create and register service instances
     const nostrmarketService = new NostrmarketService()
     container.provide(SERVICE_TOKENS.NOSTRMARKET_SERVICE, nostrmarketService)
     
-    // Initialize the service (will handle dependency injection)
+    const paymentMonitorService = new PaymentMonitorService()
+    container.provide(SERVICE_TOKENS.PAYMENT_MONITOR, paymentMonitorService)
+    
+    // Initialize services (will handle dependency injection)
     await nostrmarketService.initialize({
       waitForDependencies: true,
       maxRetries: 3
@@ -56,6 +60,14 @@ export const marketModule: ModulePlugin = {
       console.warn('🛒 NostrmarketService initialization deferred:', error)
       // Service will auto-initialize when dependencies are available
     })
+    
+    await paymentMonitorService.initialize({
+      waitForDependencies: true,
+      maxRetries: 3
+    }).catch(error => {
+      console.warn('🛒 PaymentMonitorService initialization deferred:', error)
+      // Service will auto-initialize when dependencies are available
+    })
 
     // Register global components
     app.component('MarketSettings', MarketSettings)
@@ -75,6 +87,7 @@ export const marketModule: ModulePlugin = {
     
     // Clean up services
     container.remove(SERVICE_TOKENS.NOSTRMARKET_SERVICE)
+    container.remove(SERVICE_TOKENS.PAYMENT_MONITOR)
     
     console.log('✅ Market module uninstalled')
   },