feat(lint): add components-v2/pages-v2 boundary zones (no back-port)

Adds three new eslint-plugin-boundaries element zones and their matrix
rows so the GUI-redesign v2 surface is structurally isolated: v1 code
cannot import from v2 (back-porting forbidden), v2 can reach the
narrow FormField/Icon bridge via the components-foundation zone, and
pages-v2 can import from components-v2. Backed by a Vitest spec
running via the ESLint Node API (node environment; happy-dom's
document object breaks the case-police resolver). Adds a placeholder
src/components-v2/shared/X.vue so the resolver can classify the
import target during the test (unresolvable imports are not boundary-
checked by the plugin).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/app/tests/unit/boundaries-v2.spec.ts

@@ -0,0 +1,50 @@
+// @vitest-environment node
+// ESLint Node API tests must run in the Node environment — the default
+// happy-dom environment's `document` object causes case-police's dirs.cjs
+// (which uses `document.currentScript.src` for __dirname resolution)
+// to fail with "The URL must be of scheme file".
+import { fileURLToPath } from 'node:url'
+import path from 'node:path'
+import { describe, expect, it } from 'vitest'
+import { ESLint } from 'eslint'
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const rootDir = path.resolve(__dirname, '../../')
+
+const eslint = new ESLint({ cwd: rootDir })
+
+async function boundaryErrors(filePath: string, code: string) {
+  const [result] = await eslint.lintText(code, { filePath })
+
+  return result.messages.filter(m => m.ruleId === 'boundaries/element-types')
+}
+
+describe('boundaries — v2 zones', () => {
+  it('allows pages-v2 → components-v2', async () => {
+    const errs = await boundaryErrors(
+      'src/pages-v2/dashboard.vue',
+      '<script setup lang="ts">import X from \'@/components-v2/shared/X.vue\'</script><template><X /></template>',
+    )
+
+    expect(errs).toHaveLength(0)
+  })
+
+  it('allows components-v2 → components-foundation (FormField bridge)', async () => {
+    const errs = await boundaryErrors(
+      'src/components-v2/forms/Demo.vue',
+      '<script setup lang="ts">import FormField from \'@/components/forms/FormField.vue\'</script><template><FormField /></template>',
+    )
+
+    expect(errs).toHaveLength(0)
+  })
+
+  it('forbids v1 components → components-v2 (no back-porting)', async () => {
+    const errs = await boundaryErrors(
+      'src/components/organizer/Legacy.vue',
+      '<script setup lang="ts">import X from \'@/components-v2/shared/X.vue\'</script><template><X /></template>',
+    )
+
+    expect(errs.length).toBeGreaterThan(0)
+  })
+})