fix: Ensure Message Send Requires Key 🔑 (#1281)

* fix: only allow message send when key is provided when required
- create useRequiresKey hook
- pass same disabled prop to Textarea, AttachFile, and SendButton
- EndpointItem: add localization, stopPropagation, and remove commented code
- separate some hooks to new Input dir
- completely remove textareaHeight recoil state as is not needed
- update imports for moved hooks
- pass disabled prop to useTextarea

* feat: add localization to textarea placeholders

client/src/components/Chat/Input/Files/AttachFile.tsx

@@ -3,7 +3,13 @@ import { AttachmentIcon } from '~/components/svg';
 import { FileUpload } from '~/components/ui';
 import { useFileHandling } from '~/hooks';
 
-export default function AttachFile({ endpoint }: { endpoint: EModelEndpoint | '' }) {
+export default function AttachFile({
+  endpoint,
+  disabled = false,
+}: {
+  endpoint: EModelEndpoint | '';
+  disabled?: boolean | null;
+}) {
   const { handleFileChange } = useFileHandling();
   if (!supportsFiles[endpoint]) {
     return null;
@@ -13,6 +19,7 @@ export default function AttachFile({ endpoint }: { endpoint: EModelEndpoint | ''
     <div className="absolute bottom-2 left-2 md:bottom-3 md:left-4">
       <FileUpload handleFileChange={handleFileChange} className="flex">
         <button
+          disabled={!!disabled}
           type="button"
           className="btn relative p-0 text-black dark:text-white"
           aria-label="Attach files"