Chore: Upgrade to Angular v18

Chore: Upgrade to Python 3.12
Chore: Upgrade to psycopg3

bookie/src/app/core/refresh.interceptor.ts

@@ -0,0 +1,17 @@
+import { HttpInterceptorFn } from '@angular/common/http';
+import { inject } from '@angular/core';
+
+import { AuthService } from '../auth/auth.service';
+
+export const refreshInterceptor: HttpInterceptorFn = (req, next) => {
+  const authService = inject(AuthService);
+  if (!authService.isRefreshing && authService.user && authService.needsRefreshing()) {
+    authService.isRefreshing = true;
+    authService.refreshToken().subscribe({
+      next: () => {
+        authService.isRefreshing = false;
+      },
+    });
+  }
+  return next(req);
+};