feat: finish demo — Angular 22 + Material UI, role management, schema and Docker cleanup

Frontend
- Upgrade Angular 19 -> 22 (TypeScript 6, new control flow), drop unused
  packages (bootstrap, jquery, popper, ng-bootstrap, webpack)
- Move the UI to Angular Material: toolbar with user menu, tutorials list,
  add/edit forms, admin users table with role editing dialog, profile,
  home page with published tutorials, registration form, login dialog
- Guard routes: login required for add/edit/profile, admin role for /admin
- Remove the /login, Moderator and User pages, event bus, auth interceptor
  and other dead code

Backend
- Add PUT /api/users/{id}/roles (admin only) that keeps at least one admin
  and does not let an admin drop their own admin role
- Tighten security: read tutorials publicly, change them only when logged
  in, users/roles API for admins only; hide password hashes in JSON
- Remove unused Settings and Test endpoints, DTO mappers, commented code
- Flyway V2 aligns the schema with the entities (bigint ids, tutorials PK,
  identity ids); Hibernate now runs with ddl-auto: validate

Docker
- Three-stage Dockerfile (Node build, Gradle build, JRE runtime) with
  layer caching, non-root user and healthcheck; add .dockerignore
- docker-compose waits for a healthy Postgres, always rebuilds the image,
  no longer mounts the Docker socket

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

spring-angular-ui/src/app/components/profile/profile.component.html

@@ -1,26 +1,28 @@
-<div class="container" *ngIf="currentUser; else loggedOut">
-    <header class="jumbotron">
-      <h3>
-        <strong>{{ currentUser.username }}</strong> Profile
-      </h3>
-    </header>
-    <p>
-      <strong>Token:</strong>
-      {{ currentUser.accessToken.substring(0, 20) }} ...
-      {{ currentUser.accessToken.substr(currentUser.accessToken.length - 20) }}
-    </p>
-    <p>
-      <strong>Email:</strong>
-      {{ currentUser.email }}
-    </p>
-    <strong>Roles:</strong>
-    <ul>
-      <li *ngFor="let role of currentUser.roles">
-        {{ role }}
-      </li>
-    </ul>
-  </div>
-  
-  <ng-template #loggedOut>
-    Please login.
-  </ng-template>
+<div class="page narrow">
+  <mat-card appearance="outlined" class="profile-card">
+    <div class="hero">
+      <span class="avatar large">{{ user.username?.slice(0, 2) }}</span>
+      <h1 class="name">{{ user.username }}</h1>
+      <div class="roles">
+        @for (role of roles; track role) {
+          <span class="role {{ role }}">{{ roleLabel(role) }}</span>
+        }
+      </div>
+    </div>
+
+    <mat-divider></mat-divider>
+
+    <mat-list>
+      <mat-list-item>
+        <mat-icon matListItemIcon>person</mat-icon>
+        <span matListItemTitle>Username</span>
+        <span matListItemLine>{{ user.username }}</span>
+      </mat-list-item>
+      <mat-list-item>
+        <mat-icon matListItemIcon>mail</mat-icon>
+        <span matListItemTitle>Email</span>
+        <span matListItemLine>{{ user.email }}</span>
+      </mat-list-item>
+    </mat-list>
+  </mat-card>
+</div>

spring-angular-ui/src/app/components/profile/profile.component.scss

@@ -0,0 +1,20 @@
+@use '../tutorial-shared';
+@use '../user-shared';
+
+.hero {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 12px;
+  padding: 32px 16px 24px;
+}
+
+.name {
+  margin: 0;
+  font: var(--mat-sys-headline-small);
+  color: var(--mat-sys-on-surface);
+}
+
+.roles {
+  justify-content: center;
+}

spring-angular-ui/src/app/components/profile/profile.component.ts

@@ -1,18 +1,17 @@
-import { Component, OnInit } from '@angular/core';
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
+
+import { roleLabel } from 'src/app/models/role';
 import { TokenStorageService } from 'src/app/services/token-storage.service';
 
 @Component({
-    selector: 'app-profile',
-    templateUrl: './profile.component.html',
-    styleUrls: ['./profile.component.scss'],
-    standalone: false
+  selector: 'app-profile',
+  templateUrl: './profile.component.html',
+  styleUrls: ['./profile.component.scss'],
+  changeDetection: ChangeDetectionStrategy.Eager,
+  standalone: false
 })
-export class ProfileComponent implements OnInit {
-  currentUser: any;
-
-  constructor(private token: TokenStorageService) { }
-
-  ngOnInit(): void {
-    this.currentUser = this.token.getUser();
-  }
-}
+export class ProfileComponent {
+  readonly user = inject(TokenStorageService).getUser();
+  readonly roles: string[] = this.user.roles ?? [];
+  readonly roleLabel = roleLabel;
+}