feat(autolink): add create extension package (#2587)

## Summary
- Add the create-lynx-extension CLI for scaffolding Native Autolink Lynx
extension packages.
- Maintain generated extension files in template-* directories, with
placeholder rendering for package names, Android/iOS identifiers, and
selected Native Module / Element / Service APIs.
- Wire the package into workspace references, lockfile, changeset,
CODEOWNERS, npm package files, and Native Autolink authoring
instructions.

## Validation
- pnpm --filter create-lynx-extension test
- pnpm --filter create-lynx-extension build
- pnpm exec tsc --build
packages/lynx/create-lynx-extension/tsconfig.json --pretty false
- pnpm eslint packages/lynx/create-lynx-extension/src/index.ts
packages/lynx/create-lynx-extension/src/cli.ts
packages/lynx/create-lynx-extension/test/create.test.ts
- pnpm dprint check .changeset/native-create-extension.md
.github/autolink-extension.instructions.md CODEOWNERS
packages/lynx/create-lynx-extension packages/lynx/tsconfig.json
- node packages/lynx/create-lynx-extension/dist/cli.js --dir <tmp>/demo
--types native-module,element,service --package-name
@example/lynx-button --android-package com.example.button --module-name
ButtonModule --element-name x-button --service-name ButtonService
- npm pack --dry-run --json