feat(users): OTP delivery method picker on user creation + post-login agreement

Create User dialog now has a mandatory Email/Mobile OTP delivery method
picker (styled as a pill toggle) alongside the existing fields.

Adds a new post-login agreement acceptance dialog: right after the existing
2FA flow (TwoFactorAuthenticationComponent) succeeds, or immediately after
login for users without 2FA, the user must accept the bank's current
agreement/disclaimer at least once before reaching the app.

Also adds a "Manage User Agreement" admin screen (System section) to publish
versioned agreement text without a code deploy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/system/manage-user-agreement/user-agreement.service.ts

@@ -0,0 +1,41 @@
+/**
+ * Copyright since 2025 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+import { Injectable, inject } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Observable } from 'rxjs';
+
+/** A single published version of the bank's user agreement/warning text. */
+export interface UserAgreement {
+  id: number;
+  version: number;
+  title: string;
+  body: string;
+  isActive?: boolean;
+  createdByUsername?: string;
+  createdOn?: string | number[];
+}
+
+@Injectable({ providedIn: 'root' })
+export class UserAgreementService {
+  private http = inject(HttpClient);
+
+  /** List all published versions, newest first. */
+  getAll(): Observable<UserAgreement[]> {
+    return this.http.get<UserAgreement[]>('/useragreements');
+  }
+
+  /** The currently-active version — the one new users must accept. */
+  getActive(): Observable<UserAgreement> {
+    return this.http.get<UserAgreement>('/useragreements/active');
+  }
+
+  /** Publish a new version. The backend deactivates the previous active row automatically. */
+  create(data: { title: string; body: string }): Observable<{ resourceId: number }> {
+    return this.http.post<{ resourceId: number }>('/useragreements', data);
+  }
+}