Chore: Upgrade to Angular v18

Chore: Upgrade to Python 3.12
Chore: Upgrade to psycopg3

bookie/src/app/modifiers/modifier-list.resolver.ts

@@ -0,0 +1,10 @@
+import { inject } from '@angular/core';
+import { ResolveFn } from '@angular/router';
+
+import { Modifier } from '../core/modifier';
+
+import { ModifierService } from './modifier.service';
+
+export const modifierListResolver: ResolveFn<Modifier[]> = () => {
+  return inject(ModifierService).list();
+};