1.3.6 Toast Notification Pattern: Add centralized ToastService abstraction

- Create ToastService extending BaseService with context-specific toast methods
- Add useToast composable for convenient dependency injection access
- Provide standardized toast patterns: auth, payment, clipboard, operations
- Include async operation support with automatic loading/success/error states
- Integrate with DI container and base module for automatic initialization
- Demonstrate refactoring in LoginDialog.vue with context-specific methods
- Eliminate duplicate vue-sonner imports across 20+ files for better maintainability
- Support custom ToastOptions interface with full TypeScript compatibility

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

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

src/core/di-container.ts

@@ -122,6 +122,9 @@ export const SERVICE_TOKENS = {
   // Storage services
   STORAGE_SERVICE: Symbol('storageService'),
   
+  // Toast services
+  TOAST_SERVICE: Symbol('toastService'),
+  
   // Market services
   MARKET_STORE: Symbol('marketStore'),
   PAYMENT_MONITOR: Symbol('paymentMonitor'),