feat(dx): gen:context generator (WP-44)

npm run gen:context scaffolds a bounded context: folders + starter page, the @<ctx>/*
tsconfig alias, a dependency-cruiser boundary entry, and a lazy authGuard route.

Refactors .dependency-cruiser.js's per-context contextRule calls into a single
CONTEXT_ALLOWED map that every rule derives from, so adding a context is really one
config entry (verified behavior-preserving: same dep:check counts, same graph output).

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

plop-templates/context.page.hbs

@@ -0,0 +1,17 @@
+import { Component } from '@angular/core';
+import { PageShellComponent } from '@shared/layout/page-shell/page-shell.component';
+
+/**
+ * Scaffolded by `gen:context` (WP-44) — replace with the `{{dashCase name}}` context's first
+ * feature slice (the `new-feature` skill: domain first, then infrastructure/application, UI last).
+ */
+@Component({
+  selector: 'app-{{dashCase name}}-page',
+  imports: [PageShellComponent],
+  template: `
+    <app-page-shell heading="{{titleCase name}}">
+      <p>Scaffolded by gen:context — build the first feature here.</p>
+    </app-page-shell>
+  `,
+})
+export class {{pascalCase name}}Page {}