refactor: strip WP-/RB- ticket refs from apps and libs (RD-18)

204 WP-NN/RB-NN comments named a closed ticket instead of the code they
sit next to. git blame already records history and stays correct when
code moves; the comment does not. This sweep removes the reference and
keeps the sentence, across 95 files in apps/ and libs/ plus the
behaviour-spec generator's header text.

Eleven references stay: five story files justify an a11y disable per
the README's rule, and one line in a11y.mdx documents that convention.
Two sentences needed a rewrite, not a deletion, so the reference's
meaning survives its removal. behaviour-spec.mdx is regenerated, not
hand-edited.

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

apps/ssp/src/app/brief/ui/passage-picker/passage-picker.component.ts

@@ -10,8 +10,8 @@ import { LibraryPassage } from '@brief/domain/brief';
     inserts ALL checked passages at once (a single message upstream) — there is no
     single-insert path. Presentational: emits the chosen passages in list order.
 
-    Superseded by `besluit-panel` (WP-27's guided drafting): no consumer left in
-    `src/app` outside its own story (WP-28 audit). Kept for now rather than deleted
+    Superseded by `besluit-panel`'s guided drafting: no consumer left in
+    `src/app` outside its own story. Kept for now rather than deleted
     in-flight of an unrelated WP; a future cleanup can remove it. */
 @Component({
   selector: 'app-passage-picker',
@@ -87,7 +87,7 @@ export class PassagePickerComponent {
   protected checked = signal<Record<string, boolean>>({});
   protected query = signal('');
   /** Client-side filter on label + rendered content text — the library is small, so no
-      server search (WP-27). Placeholder keys are searchable too (see `textOf`). */
+      server search. Placeholder keys are searchable too (see `textOf`). */
   protected filtered = computed(() => {
     const q = this.query().trim().toLowerCase();
     if (!q) return this.passages();