Implement enhanced login functionality with JWT, role-based permissions, and frontend integration

Added JWT-based login dialog with form validation and secure token handling on the frontend. Updated backend with role-based access control, privilege management, and refined security configurations. Extended database schema for user privileges and permissions.

frontend/src/app/login/login.component.html

@@ -0,0 +1,18 @@
+<h2 mat-dialog-title>Login</h2>
+<div mat-dialog-content>
+  <form [formGroup]="loginForm">
+    <mat-form-field appearance="fill" style="width: 100%">
+      <mat-label>Enter your code</mat-label>
+      <input matInput formControlName="code" type="text">
+      <mat-error *ngIf="formHasError()">
+        Code is required
+      </mat-error>
+    </mat-form-field>
+  </form>
+</div>
+<div mat-dialog-actions align="end">
+  <button mat-button (click)="onCancel()">Cancel</button>
+  <button mat-flat-button color="primary" (click)="onSubmit()" [disabled]="!loginForm.valid">
+    Submit
+  </button>
+</div>