Adding CodeMirror language support

CodeMirrorEditor loads language extensions on demand through languageLoader.ts. Keep language loading centralized there so every consumer gets the same behavior without adding a language package to the initial editor bundle.

Add a language

The examples below add Python support. Replace all Python references with the language you are adding.

Add the CodeMirror language package to @grafana/ui from the repository root:
bash
```
yarn workspace @grafana/ui add @codemirror/lang-python
```
Commit the resulting changes to packages/grafana-ui/package.json and yarn.lock.

Add the public language name to CodeMirrorEditorLanguage in types.ts:

export type CodeMirrorEditorLanguage = 'json' | 'python' | 'sql';

Add an asynchronous loader in languageLoader.ts. Give the import a stable chunk name and return the extension created by the language package:

const loadPython = async (): Promise<CodeMirrorExtension> =>
  (await import(/* webpackChunkName: "codemirror-lang-python" */ '@codemirror/lang-python')).python();

Register the loader in resolveLoad:
ts
```
case 'python':
  return { cacheKey: 'python', load: loadPython };
```
The cache key must identify the resulting extension. If a language has configuration that changes the extension, include that configuration in the cache key, as the SQL dialect loader does. Thread new configuration through CodeMirrorEditorProps, useLanguageExtension, and LoadLanguageOptions rather than importing the language directly in a consumer.
Add the language to languageOptions in CodeEditor.story.tsx so it can be selected in Storybook, and add focused coverage to languageLoader.test.ts.

Verify the change

Run the shared editor tests and formatting checks from the repository root:

bash

yarn jest --no-watch packages/grafana-ui/src/components/CodeMirror/languageLoader.test.ts packages/grafana-ui/src/components/CodeMirror/CodeEditor.test.tsx
yarn prettier --check packages/grafana-ui/src/components/CodeMirror/ADDING_LANGUAGES.md

Use the CodeMirrorEditor Storybook story to confirm syntax highlighting and any language-specific behavior in the browser.