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/base/BaseService.ts

@@ -46,6 +46,7 @@ export abstract class BaseService {
   protected authService: any = null
   protected visibilityService: any = null
   protected storageService: any = null
+  protected toastService: any = null
   
   // Service state
   public readonly isInitialized: Ref<boolean> = ref(false)
@@ -136,6 +137,7 @@ export abstract class BaseService {
         this.authService = tryInjectService(SERVICE_TOKENS.AUTH_SERVICE)
         this.visibilityService = tryInjectService(SERVICE_TOKENS.VISIBILITY_SERVICE)
         this.storageService = tryInjectService(SERVICE_TOKENS.STORAGE_SERVICE)
+        this.toastService = tryInjectService(SERVICE_TOKENS.TOAST_SERVICE)
         
         // Check if all required dependencies are available
         const missingDeps = this.getMissingDependencies()
@@ -186,6 +188,9 @@ export abstract class BaseService {
     if (deps.includes('StorageService') && !this.storageService) {
       missing.push('StorageService')
     }
+    if (deps.includes('ToastService') && !this.toastService) {
+      missing.push('ToastService')
+    }
     
     return missing
   }
@@ -271,6 +276,7 @@ export abstract class BaseService {
       this.authService = null
       this.visibilityService = null
       this.storageService = null
+      this.toastService = null
       
       console.log(`♻️ ${this.metadata.name} disposed`)