Chore: Upgrade to Angular v18

Chore: Upgrade to Python 3.12
Chore: Upgrade to psycopg3

bookie/src/app/nav-bar/nav-bar.component.html

@@ -3,21 +3,29 @@
     <mat-icon>home</mat-icon>
     Point of Sale
   </a>
-  <a mat-button *ngIf="auth.allowed('customers')" [routerLink]="['/', 'guest-book']">
-    <mat-icon>face</mat-icon>
-    Guest Book
-  </a>
-  <a mat-button *ngIf="auth.allowed('sales')" [routerLink]="['/', 'sales']">
-    <mat-icon>receipt</mat-icon>
-    Sales
-  </a>
+  @if (auth.allowed('customers')) {
+    <a mat-button [routerLink]="['/', 'guest-book']">
+      <mat-icon>face</mat-icon>
+      Guest Book
+    </a>
+  }
+  @if (auth.allowed('sales')) {
+    <a mat-button [routerLink]="['/', 'sales']">
+      <mat-icon>receipt</mat-icon>
+      Sales
+    </a>
+  }
   <span class="fill-remaining-space"></span>
-  <button mat-button [routerLink]="['/', 'login']" *ngIf="(auth.currentUser | async) === null">
-    <mat-icon>account_box</mat-icon>
-    Login
-  </button>
-  <button mat-button [routerLink]="['/', 'logout']" *ngIf="(auth.currentUser | async)?.name as name">
-    <mat-icon>account_box</mat-icon>
-    Logout {{ name }}
-  </button>
+  @if ((auth.currentUser | async) === null) {
+    <button mat-button [routerLink]="['/', 'login']">
+      <mat-icon>account_box</mat-icon>
+      Login
+    </button>
+  }
+  @if ((auth.currentUser | async)?.name; as name) {
+    <button mat-button [routerLink]="['/', 'logout']">
+      <mat-icon>account_box</mat-icon>
+      Logout {{ name }}
+    </button>
+  }
 </mat-toolbar>