Remove old GraphiQL template implementation

With the new standalone React 18 package now fully functional, remove
the deprecated template-based implementation to reduce technical debt.

Changes:
- Deleted packages/app/src/cli/services/dev/graphiql/templates/graphiql.tsx (old template)
- Inlined DEFAULT_SHOP_QUERY constant in server.ts (was imported from deleted template)
- Server now uses React app's default content instead of server-side templates

The modern graphiql-console package handles all UI rendering and default
content through its own constants and components.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: amcaplan

packages/app/src/cli/services/dev/graphiql/server.ts

@@ -1,4 +1,3 @@
-import {defaultQuery} from './templates/graphiql.js'
 import {unauthorizedTemplate} from './templates/unauthorized.js'
 import express from 'express'
 import bodyParser from 'body-parser'
@@ -17,6 +16,20 @@ import {createRequire} from 'module'
 
 const require = createRequire(import.meta.url)
 
+// Default query for GraphiQL - matches DEFAULT_SHOP_QUERY in graphiql-console package
+const DEFAULT_SHOP_QUERY = `query shopInfo {
+  shop {
+    name
+    url
+    myshopifyDomain
+    plan {
+      displayName
+      partnerDevelopment
+      shopifyPlus
+    }
+  }
+}`
+
 class TokenRefreshError extends AbortError {
   constructor() {
     super('Failed to refresh credentials. Check that your app is installed, and try again.')
@@ -181,7 +194,7 @@ export function setupGraphiQLServer({
       storeFqdn,
       baseUrl,
       key: key ?? undefined,
-      query: query ?? defaultQuery,
+      query: query ?? DEFAULT_SHOP_QUERY,
     }
 
     // Inject config script before </head>