phase-4: add provider-abstracted ConfigService with mock bootstrap loader

src/app/core/bootstrap/providers/api-bootstrap.provider.ts

@@ -0,0 +1,16 @@
+import { Injectable } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { BootstrapConfig } from '../../../shared/models/config';
+import { ConfigProvider } from '../../config/config-provider.interface';
+
+@Injectable({ providedIn: 'root' })
+export class ApiBootstrapProvider implements ConfigProvider {
+  private readonly bootstrapUrl = '/bootstrap';
+
+  constructor(private readonly http: HttpClient) {}
+
+  loadBootstrap(): Observable<BootstrapConfig> {
+    return this.http.get<BootstrapConfig>(this.bootstrapUrl);
+  }
+}

src/app/core/bootstrap/providers/mock-bootstrap.provider.ts

@@ -0,0 +1,16 @@
+import { Injectable } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { BootstrapConfig } from '../../../shared/models/config';
+import { ConfigProvider } from '../../config/config-provider.interface';
+
+@Injectable({ providedIn: 'root' })
+export class MockBootstrapProvider implements ConfigProvider {
+  private readonly bootstrapUrl = '/assets/mock/bootstrap/bootstrap.json';
+
+  constructor(private readonly http: HttpClient) {}
+
+  loadBootstrap(): Observable<BootstrapConfig> {
+    return this.http.get<BootstrapConfig>(this.bootstrapUrl);
+  }
+}

src/app/core/config/config-provider.interface.ts

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+import { Observable } from 'rxjs';
+import { BootstrapConfig } from '../../shared/models/config';
+
+export interface ConfigProvider {
+  loadBootstrap(): Observable<BootstrapConfig>;
+}

src/app/core/config/config-provider.token.ts

@@ -0,0 +1,8 @@
+import { InjectionToken, inject } from '@angular/core';
+import { ConfigProvider } from './config-provider.interface';
+import { MockBootstrapProvider } from '../bootstrap/providers/mock-bootstrap.provider';
+
+export const CONFIG_PROVIDER = new InjectionToken<ConfigProvider>('CONFIG_PROVIDER', {
+  providedIn: 'root',
+  factory: () => inject(MockBootstrapProvider)
+});

src/app/core/config/config.service.ts

@@ -0,0 +1,35 @@
+import { Injectable, inject } from '@angular/core';
+import { Observable, throwError } from 'rxjs';
+import { catchError, shareReplay, tap } from 'rxjs/operators';
+import { BootstrapConfig } from '../../shared/models/config';
+import { CONFIG_PROVIDER } from './config-provider.token';
+
+@Injectable({ providedIn: 'root' })
+export class ConfigService {
+  private readonly provider = inject(CONFIG_PROVIDER);
+
+  private bootstrapSnapshot: BootstrapConfig | null = null;
+  private bootstrap$?: Observable<BootstrapConfig>;
+
+  loadBootstrap(forceRefresh: boolean = false): Observable<BootstrapConfig> {
+    if (!this.bootstrap$ || forceRefresh) {
+      this.bootstrap$ = this.provider.loadBootstrap().pipe(
+        tap(config => {
+          this.bootstrapSnapshot = config;
+        }),
+        shareReplay(1),
+        catchError(error => {
+          this.bootstrap$ = undefined;
+          this.bootstrapSnapshot = null;
+          return throwError(() => error);
+        })
+      );
+    }
+
+    return this.bootstrap$;
+  }
+
+  getBootstrapSnapshot(): BootstrapConfig | null {
+    return this.bootstrapSnapshot;
+  }
+}