fix(ai-chat): make the new-chat composer text-only so a sticker or file first move cannot strand the user

src/app/features/bots/BotConversations.tsx

@@ -63,6 +63,7 @@ function NewChatComposer({ preset, room }: { preset: BotPreset; room: Room }) {
           roomId={room.roomId}
           fileDropContainerRef={fileDropRef}
           onSend={handleSend}
+          textOnly
         />
       </div>
     </div>

src/app/features/room/RoomInput.tsx

@@ -205,9 +205,14 @@ interface RoomInputProps {
   // freshly-rooted thread (the just-sent top-level event IS the thread root).
   // Channel / DM / thread composers omit it and stay fire-and-forget.
   onSend?: (eventId: string) => void;
+  // Text-only mode: hides the file/sticker affordances and no-ops file
+  // paste/drop. The AI "new chat" landing uses it because only a text send
+  // navigates into the freshly-rooted thread (onSend) — a sticker/file first
+  // move would otherwise strand the user on the landing.
+  textOnly?: boolean;
 }
 export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
-  ({ editor, fileDropContainerRef, roomId, room, threadId, onSend }, ref) => {
+  ({ editor, fileDropContainerRef, roomId, room, threadId, onSend, textOnly }, ref) => {
     const { t } = useTranslation();
     const mx = useMatrixClient();
     const useAuthentication = useMediaAuthentication();
@@ -276,6 +281,9 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
 
     const handleFiles = useCallback(
       async (files: File[]) => {
+        // Text-only composer (AI new-chat landing) ignores every file vector —
+        // picker, paste and drop all funnel through here.
+        if (textOnly) return;
         setUploadBoard(true);
         const safeFiles = files.map(safeFile);
         const fileItems: TUploadItem[] = [];
@@ -309,7 +317,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
           item: fileItems,
         });
       },
-      [setSelectedFiles, room]
+      [setSelectedFiles, room, textOnly]
     );
     const pickFile = useFilePicker(handleFiles, true);
     const handlePaste = useFilePasteHandler(handleFiles);
@@ -764,7 +772,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
           </UploadBoard>
         )}
         <Overlay
-          open={dropZoneVisible}
+          open={dropZoneVisible && !textOnly}
           backdrop={<OverlayBackdrop />}
           style={{ pointerEvents: 'none' }}
         >
@@ -873,9 +881,9 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
               gap="200"
               style={{ padding: `${toRem(2)} ${toRem(8)} ${toRem(4)}` }}
             >
-              {plusButton}
+              {!textOnly && plusButton}
               <Box grow="Yes" />
-              {emojiButton}
+              {!textOnly && emojiButton}
               {sendButton}
             </Box>
           }