review fixes

ui/src/app/services/toast.service.ts

@@ -0,0 +1,86 @@
+import { Injectable, signal } from '@angular/core';
+
+export type ToastLevel = 'info' | 'success' | 'error';
+
+export interface ToastAction {
+  label: string;
+  value: boolean;
+  primary?: boolean;
+}
+
+export interface Toast {
+  id: number;
+  level: ToastLevel;
+  message: string;
+  actions?: ToastAction[];
+  /** Resolver for confirm() toasts; resolved when the user picks an action or dismisses. */
+  _resolve?: (value: boolean) => void;
+}
+
+/**
+ * Lightweight non-blocking notification service. Replaces the blocking
+ * window.alert()/confirm() dialogs that previously littered the app component.
+ */
+@Injectable({ providedIn: 'root' })
+export class ToastService {
+  private counter = 0;
+  readonly toasts = signal<Toast[]>([]);
+
+  info(message: string): void {
+    this.show('info', message, 4000);
+  }
+
+  success(message: string): void {
+    this.show('success', message, 4000);
+  }
+
+  error(message: string): void {
+    this.show('error', message, 8000);
+  }
+
+  /**
+   * Show a confirmation toast with confirm/cancel actions. Resolves true when
+   * confirmed, false when cancelled or auto-dismissed.
+   */
+  confirm(message: string, confirmLabel = 'OK', cancelLabel = 'Cancel'): Promise<boolean> {
+    return new Promise<boolean>((resolve) => {
+      const id = ++this.counter;
+      this.toasts.update((list) => [
+        ...list,
+        {
+          id,
+          level: 'info',
+          message,
+          actions: [
+            { label: cancelLabel, value: false },
+            { label: confirmLabel, value: true, primary: true },
+          ],
+          _resolve: resolve,
+        },
+      ]);
+    });
+  }
+
+  respond(id: number, value: boolean): void {
+    const toast = this.toasts().find((t) => t.id === id);
+    toast?._resolve?.(value);
+    this.remove(id);
+  }
+
+  dismiss(id: number): void {
+    const toast = this.toasts().find((t) => t.id === id);
+    // A confirm toast dismissed without an explicit choice resolves to false.
+    toast?._resolve?.(false);
+    this.remove(id);
+  }
+
+  private remove(id: number): void {
+    this.toasts.update((list) => list.filter((t) => t.id !== id));
+  }
+
+  private show(level: ToastLevel, message: string, autoDismissMs: number): void {
+    const id = ++this.counter;
+    this.toasts.update((list) => [...list, { id, level, message }]);
+    setTimeout(() => this.remove(id), autoDismissMs);
+  }
+}