refactor(gui-v2): delete X.vue stub, repoint 2 boundary refs to StatusTag, add shared/* regression locks

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/app/src/components-v2/shared/X.vue

@@ -1,10 +0,0 @@
-<script setup lang="ts">
-// Boundary-test placeholder — do not import in production code.
-// Exists so eslint-plugin-boundaries can resolve @/components-v2/shared/X.vue
-// in unit tests (the resolver skips unresolvable imports).
-// TODO TECH-WS-GUI-REDESIGN: replace with real shared components.
-</script>
-
-<template>
-  <div />
-</template>