DES-51: add Nage phone input foundation (#28445)

## Summary
- Recreates the DES-51 Nage phone input foundation on a fresh branch
from current `origin/main` to avoid the superseded PR's lockfile guard
history issue.
- Introduces E.164-only parsing helpers plus an Origin
`PhoneInput`/`Field` backed component using local round country flag
assets.
- Refactors the field around a single parsed draft model, keeps external
`value` as canonical E.164, and delays internal validation visibility
until blur unless a previously accepted value becomes invalid.
- Covers country-change behavior, controlled value sync, validation
notifications, repeated invalid edits, delayed internal error
visibility, and the `+447911123456` Crown Dependency case as `GG`, with
field tests using real Origin components and role-based queries.

## Scope
- Foundation files only under
`js/apps/private/site/src/uma-nage/components/phone-input/`.
- No package version bump files, KYB, payouts, settings, or other
product callsite migrations in this PR.
- Supersedes #28414.

## Test plan
- `mise exec -- node -v` from `js` — `v20.19.6`.
- `mise exec -- yarn workspace @lightsparkdev/site exec prettier --check
src/uma-nage/components/phone-input/NagePhoneInputField.tsx
src/uma-nage/components/phone-input/NagePhoneInputField.test.tsx` from
`js` — passed.
- `mise exec -- yarn workspace @lightsparkdev/site exec eslint
src/uma-nage/components/phone-input/NagePhoneInputField.tsx
src/uma-nage/components/phone-input/NagePhoneInputField.test.tsx` from
`js` — passed.
- `mise exec -- yarn workspace @lightsparkdev/site exec vitest run
src/uma-nage/components/phone-input/NagePhoneInputField.test.tsx
src/uma-nage/components/phone-input/phoneNumber.test.ts` from `js` — 30
tests passed.

Made with [Cursor](https://cursor.com)

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
GitOrigin-RevId: 5ada43a118245619dbf0fc52058399ed8e336980

Author: 2 people

packages/ui/package.json

@@ -19,6 +19,10 @@
       "import": "./dist/components/*.js",
       "require": "./dist/components/*.cjs"
     },
+    "./components/CountryFlag": {
+      "import": "./dist/components/CountryFlag/index.js",
+      "require": "./dist/components/CountryFlag/index.cjs"
+    },
     "./components/typography": {
       "import": "./dist/components/typography/index.js",
       "require": "./dist/components/typography/index.cjs"