ADD - expand phone application platform

Add the Companies app, resilient call handling, custom app registry, vendor compatibility, storage policies, frontend bridge, tests, documentation, config, locale, and SQL migrations.

frontend/src/utils/windowMessages.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from 'vitest'
+
+import { isTrustedRootMessageSource } from '@/utils/windowMessages'
+
+describe('root window message source', () => {
+  it('accepts native NUI messages and messages posted by the root window', () => {
+    const rootWindow = {} as Window
+
+    expect(isTrustedRootMessageSource(null, rootWindow)).toBe(true)
+    expect(isTrustedRootMessageSource(rootWindow, rootWindow)).toBe(true)
+  })
+
+  it('rejects messages posted by child frames', () => {
+    const rootWindow = {} as Window
+    const childFrame = {} as Window
+
+    expect(isTrustedRootMessageSource(childFrame, rootWindow)).toBe(false)
+  })
+})