fix(front): set up Monaco workers for GraphQL playground (#21620)

## Problem

The GraphQL API playground (`/settings/playground/graphql/core`) crashes
with:

```
Uncaught Error: Cannot read properties of undefined (reading 'toUrl')
  at FileAccessImpl.toUri (monaco-editor)
  at WorkerManager.getLanguageServiceWorker (graphqlMode)
  at DiagnosticsAdapter._doValidate (graphqlMode)
```

## Root cause

GraphiQL 5 (adopted in the React 19 migration, #21531) renders its
editors with **Monaco** instead of CodeMirror. Monaco spawns web workers
for GraphQL validation/autocomplete and needs a
`globalThis.MonacoEnvironment.getWorker` factory. None was ever
configured, so Monaco fell back to a main-thread worker whose URL
resolves to `undefined` → the `toUrl` crash.

## Why not the official helper

GraphiQL ships `@graphiql/react/setup-workers/vite`, but its bundled
`?worker` imports are incompatible with our rolldown-based Vite setup:
- **pre-bundled** (in `optimizeDeps`): esbuild's optimizer can't process
`?worker` → the dep 504s and the page fails to load the chunk.
- **excluded** from `optimizeDeps`: rolldown tries to load
`editor.worker.js?worker` as a literal path → `UNLOADABLE_DEPENDENCY`,
crashing the dev server.

## Fix

- Register `MonacoEnvironment.getWorker` in **app source**
(`setupGraphiqlMonacoWorkers.ts`), where Vite's worker plugin handles
`?worker` reliably, and side-effect import it from
`GraphQLPlayground.tsx` before GraphiQL mounts.
- Align `monaco-editor` to `0.52.2` and add `monaco-graphql@1.8.0` as
direct deps so the workers run on the **same deduped Monaco instance**
GraphiQL uses on the main thread (a version mismatch would break the
worker protocol).

## Verification

Ran the playground locally against the dev server:
- Editor renders, syntax highlighting works, operation name parses
(GraphQL language service alive).
- All three worker files (`editor`, `json`, `graphql`) load `200` and
instantiate as module workers.
- Console is free of `toUrl` / `Cannot read` errors and the "must define
MonacoEnvironment.getWorker" warning.
- `oxlint`, `oxfmt`, and `nx typecheck twenty-front` pass.

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packages/twenty-front/src/modules/settings/playground/components/GraphQLPlayground.tsx

@@ -1,3 +1,4 @@
+import '@/settings/playground/utils/setupGraphiqlMonacoWorkers';
 import {
   isPlaygroundApiKeyFresh,
   playgroundApiKeyState,

packages/twenty-front/src/modules/settings/playground/utils/setupGraphiqlMonacoWorkers.ts

@@ -0,0 +1,22 @@
+import { type Environment } from 'monaco-editor';
+import EditorWorker from 'monaco-editor/esm/vs/editor/editor.worker.js?worker';
+import JsonWorker from 'monaco-editor/esm/vs/language/json/json.worker.js?worker';
+import GraphqlWorker from 'monaco-graphql/esm/graphql.worker.js?worker';
+
+// GraphiQL 5's Monaco editors need a worker factory; without it Monaco throws "Cannot read properties of undefined (reading 'toUrl')".
+const monacoEnvironment: Environment = {
+  getWorker: (_workerId, label) => {
+    switch (label) {
+      case 'json':
+        return new JsonWorker();
+      case 'graphql':
+        return new GraphqlWorker();
+      default:
+        return new EditorWorker();
+    }
+  },
+};
+
+(
+  globalThis as unknown as { MonacoEnvironment?: Environment }
+).MonacoEnvironment = monacoEnvironment;