refactor: rename Application → Aanvraag across the wire (Step 1/8)

The wire said Application, the domain said Aanvraag — one aggregate with
two names at every hop. Rename the backend DTOs and the /applications
route to /aanvragen, regenerate the typed client, and rename the frontend
adapter/store to match.

Renamed: ApplicationSummaryDto/DetailDto, CreateApplicationRequest,
SubmitApplicationRequest/Response → Aanvraag* equivalents;
ApplicationsAdapter/Store → AanvragenAdapter/Store;
applications.adapter.ts/applications.store.ts → aanvragen.*.

Left untouched: the admin Case/Zaak vocabulary (/admin/cases,
AdminCasesStore) — a separate read model, not part of this rename; the
internal BigRegister.Domain.Applications namespace and the Applications
EF table (renaming those needs a new EF migration, out of scope here).

Part of the dashboard-readability refactor (see the approved plan).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/ssp/src/app/registratie/application/draft-sync.spec.ts

@@ -2,14 +2,14 @@ import { ApplicationRef, signal } from '@angular/core';
 import { TestBed } from '@angular/core/testing';
 import { ActivatedRoute, Router } from '@angular/router';
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
-import { ApplicationsAdapter } from '@registratie/infrastructure/applications.adapter';
+import { AanvragenAdapter } from '@registratie/infrastructure/aanvragen.adapter';
 import { createDraftSync, DraftSnapshot } from './draft-sync';
 
-function setup(adapter: Partial<ApplicationsAdapter>) {
+function setup(adapter: Partial<AanvragenAdapter>) {
   const navigate = vi.fn().mockResolvedValue(true);
   TestBed.configureTestingModule({
     providers: [
-      { provide: ApplicationsAdapter, useValue: adapter },
+      { provide: AanvragenAdapter, useValue: adapter },
       { provide: Router, useValue: { navigate } },
       { provide: ActivatedRoute, useValue: { snapshot: { queryParamMap: { get: () => null } } } },
     ],