feat(WP-67): merge behandelportal into this repo as a monorepo

Restructures into apps/ssp + apps/behandelportal (two Angular projects)
plus libs/shared + libs/beheer (cross-app libraries), replacing WP-61's
separate sibling repo. That split had already produced real drift: a
hand-vendored copy of the backend's OpenAPI doc, a shared/ui+layout tree
forked and silently diverging (7 files), and beheer + the styles.scss
token bridge duplicated byte-for-byte across both repos.

- git mv the SSP's src/app/* into apps/ssp/; fold shared/, beheer/,
  environments/, the Storybook docs/*.mdx, and styles.scss into
  libs/shared + libs/beheer (all confirmed identical between the two
  repos before merging). auth stays deliberately duplicated per
  ADR-0002 (actor-specific, expected to diverge) - amended there.
- One generated API client (libs/shared), no more vendored swagger.json.
- .dependency-cruiser split into a base factory + one config per app,
  and Storybook into .storybook-ssp/.storybook-behandelportal - both
  forced by the @auth/* alias resolving to different directories per app.
- SiteHeaderComponent/ShellComponent gained HEADER_NAV_ITEMS/
  HEADER_ADMIN_LINKS/DEBUG_PANEL injection tokens so each app supplies
  its own nav/admin-links/dev-panel instead of one being hardcoded.
- CLAUDE.md, ARCHITECTURE.md, dependencies.md, and ADR-0002 updated;
  WP-67 backlog entry documents the full decision trail.

npm run ci green (lint, dep:check x2, 360 tests across ssp/
behandelportal/shared/beheer, both localized builds, backend tests,
snippet + api-client drift); both dev servers, both Storybook
instances, and docker compose verified working.

The old sibling repo (/home/eho/repos/behandelportal) is left
untouched, not deleted.

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

libs/shared/src/ui/skeleton/skeleton.component.ts

@@ -0,0 +1,59 @@
+import { Component, OnDestroy, OnInit, computed, input, signal } from '@angular/core';
+
+// CIBG-GAP EXTENSION: Laadindicatie — no vendored loading-skeleton class exists
+// (verified absent from huisstijl.min.css); hand-rolled shimmer, see cibg-gaps.mdx.
+/** Atom: skeleton placeholder (grey shimmer). Delay-gated so it never flashes
+    on fast responses. Render `count` lines shaped roughly like the content. */
+@Component({
+  selector: 'app-skeleton',
+  styles: [
+    `
+      :host {
+        display: block;
+      }
+      .sk {
+        background: linear-gradient(
+          90deg,
+          var(--rhc-color-cool-grey-200) 25%,
+          var(--rhc-color-cool-grey-100) 37%,
+          var(--rhc-color-cool-grey-200) 63%
+        );
+        background-size: 400% 100%;
+        animation: sh 1.4s ease infinite;
+        border-radius: var(--rhc-border-radius-md);
+        margin-block-end: var(--rhc-space-max-lg);
+      }
+      @keyframes sh {
+        0% {
+          background-position: 100% 0;
+        }
+        100% {
+          background-position: 0 0;
+        }
+      }
+    `,
+  ],
+  template: `
+    @if (visible()) {
+      @for (l of lines(); track $index) {
+        <div class="sk" aria-hidden="true" [style.width]="width()" [style.height]="height()"></div>
+      }
+    }
+  `,
+})
+export class SkeletonComponent implements OnInit, OnDestroy {
+  width = input('100%');
+  height = input('1rem');
+  count = input(1);
+  delay = input(150);
+  protected visible = signal(false);
+  protected lines = computed(() => Array(this.count()).fill(0));
+  private timer?: ReturnType<typeof setTimeout>;
+
+  ngOnInit() {
+    this.timer = setTimeout(() => this.visible.set(true), this.delay());
+  }
+  ngOnDestroy() {
+    clearTimeout(this.timer);
+  }
+}

libs/shared/src/ui/skeleton/skeleton.stories.ts

@@ -0,0 +1,17 @@
+import type { Meta, StoryObj } from '@storybook/angular';
+import { SkeletonComponent } from './skeleton.component';
+
+const meta: Meta<SkeletonComponent> = {
+  title: 'Design System/Atoms/Skeleton',
+  component: SkeletonComponent,
+  args: { delay: 0 },
+  parameters: {
+    cibgGap: true,
+    docs: { description: { component: 'CIBG-gap extension — see Foundations/CIBG Gap Register.' } },
+  },
+};
+export default meta;
+type Story = StoryObj<SkeletonComponent>;
+
+export const SingleLine: Story = { args: { width: '60%', height: '1rem' } };
+export const CardPlaceholder: Story = { args: { height: '2.5rem', count: 6 } };