fix(primevue): switch installer to named export to stop double-registration

main.ts explicitly calls installPrimeVue(app) AFTER registerPlugins(app)
per the comment in main.ts ("so PrimeVue lives outside the Vuexy @core
machine"). The intent was a single registration site outside the
auto-discovery loop.

Bug: registerPlugins (src/@core/utils/plugins.ts) globs
plugins/*/index.{ts,js} eagerly and invokes the `default` export of
each match. plugins/primevue/index.ts was exporting installPrimeVue
as the default, so registerPlugins also picked it up and called it.
End result: PrimeVue and its three services (Toast, Confirmation,
Dialog) were each registered twice on every app boot. Visible
symptoms: duplicate Toast emissions on a single Toast.add() call,
and ConfirmationService callbacks firing twice for one user
confirmation.

Fix: convert `export default function installPrimeVue` to a NAMED
export, and update main.ts's import to `{ installPrimeVue }`. The
registerPlugins glob still picks up the module path but the
`pluginImportModule.default?.(app)` invocation becomes a no-op via
optional chaining (no default export to call). main.ts remains the
single registration site.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/app/src/main.ts

@@ -12,7 +12,7 @@ import { router } from '@/plugins/1.router'
 
 import App from '@/App.vue'
 import { registerPlugins } from '@core/utils/plugins'
-import installPrimeVue from '@/plugins/primevue'
+import { installPrimeVue } from '@/plugins/primevue'
 
 // Styles
 import '@styles/tailwind.css'

apps/app/src/plugins/primevue/index.ts

@@ -6,6 +6,16 @@
 // Per RFC-WS-FRONTEND-PRIMEVUE AD-2: darkModeSelector matches Vuexy's
 // `.dark` class convention so existing skin-toggle plumbing continues
 // to work during the F3–F6 parallel-mode window.
+//
+// Exported as a NAMED function (no `export default`) on purpose: the
+// Vuexy registerPlugins() helper (src/@core/utils/plugins.ts) globs
+// plugins/*/index.{ts,js} and invokes the `default` export of each
+// match. A default export here would cause PrimeVue + its three
+// services to register twice — once via registerPlugins, once via the
+// explicit installPrimeVue(app) call in main.ts. The named export
+// keeps the explicit installer in main.ts as the single registration
+// site, which is the design intent (decouple PrimeVue from the Vuexy
+// @core machine so F6 can delete @core/ without affecting PrimeVue).
 
 import type { App } from 'vue'
 import PrimeVue from 'primevue/config'
@@ -17,7 +27,7 @@ import nl from 'primelocale/nl.json'
 import { CrewliPreset } from './theme'
 import { ptDefaults } from './defaults'
 
-export default function installPrimeVue(app: App) {
+export function installPrimeVue(app: App) {
   app.use(PrimeVue, {
     theme: {
       preset: CrewliPreset,