fix(richtext-lexical): enable select inputs with ctrl+a or cmd+a (#12453)

Fixes #6871

To review this PR, use `pnpm dev lexical` and the auto-created document
in the `lexical fields` collection. Select any input within the blocks
and press `cmd+a`. The selection should contain the entire input.

I made sure that `cmd+a` still works fine inside the editor but outside
of inputs.

packages/richtext-lexical/src/lexical/LexicalEditor.tsx

@@ -19,6 +19,7 @@ import { DraggableBlockPlugin } from './plugins/handles/DraggableBlockPlugin/ind
 import { InsertParagraphAtEndPlugin } from './plugins/InsertParagraphAtEnd/index.js'
 import { MarkdownShortcutPlugin } from './plugins/MarkdownShortcut/index.js'
 import { NormalizeSelectionPlugin } from './plugins/NormalizeSelection/index.js'
+import { SelectAllPlugin } from './plugins/SelectAllPlugin/index.js'
 import { SlashMenuPlugin } from './plugins/SlashMenu/index.js'
 import { TextPlugin } from './plugins/TextPlugin/index.js'
 import { LexicalContentEditable } from './ui/ContentEditable.js'
@@ -111,6 +112,7 @@ export const LexicalEditor: React.FC<
         <InsertParagraphAtEndPlugin />
         <DecoratorPlugin />
         <TextPlugin features={editorConfig.features} />
+        <SelectAllPlugin />
         <OnChangePlugin
           // Selection changes can be ignored here, reducing the
           // frequency that the FieldComponent and Payload receive updates.

packages/richtext-lexical/src/lexical/plugins/SelectAllPlugin/index.tsx

@@ -0,0 +1,32 @@
+import { useLexicalComposerContext } from '@lexical/react/LexicalComposerContext'
+import { $getSelection, COMMAND_PRIORITY_LOW, SELECT_ALL_COMMAND } from 'lexical'
+import { useEffect } from 'react'
+
+/**
+ * Allows to select inputs with `ctrl+a` or `cmd+a`.
+ * Required because Lexical preventDefault the event.
+ * see: https://github.com/payloadcms/payload/issues/6871
+ */
+export function SelectAllPlugin() {
+  const [editor] = useLexicalComposerContext()
+
+  useEffect(() => {
+    return editor.registerCommand(
+      SELECT_ALL_COMMAND,
+      () => {
+        const selection = $getSelection()
+        if (selection) {
+          return false
+        }
+        const activeElement = document.activeElement
+        if (activeElement instanceof HTMLInputElement) {
+          activeElement.select()
+        }
+        return true
+      },
+      COMMAND_PRIORITY_LOW,
+    )
+  }, [editor])
+
+  return null
+}