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/brief.page.ts

@@ -167,7 +167,7 @@ export class BriefPage {
     void this.store.resetDemo();
   }
 
-  /** Typed narrowing for the `<app-async>` loaded slot — see WP-06: a structural
+  /** Typed narrowing for the `<app-async>` loaded slot: a structural
       directive's context can't inherit a generic from a sibling host input, so the
       Success value is unwrapped here instead of through `let-`. */
   protected readonly loaded = computed(() => {
@@ -179,7 +179,7 @@ export class BriefPage {
     void this.store.load();
   }
 
-  /** Ctrl/Cmd+Z = undo, Ctrl/Cmd+Shift+Z = redo (WP-27). Ignored while focus is in the
+  /** Ctrl/Cmd+Z = undo, Ctrl/Cmd+Shift+Z = redo. Ignored while focus is in the
       rich-text editor or a form control, so the browser's own text undo keeps working
       there — our shell-level undo is for structural edits (add/remove/reorder blocks). */
   protected onKey(e: KeyboardEvent) {