refactor(files): optimize file deletion logic for better performance

Refactor the file deletion logic in FilesStore to precompute prefixes and iterate through files only once. This reduces the complexity of nested loops and improves performance by applying all deletions in a single update to the store. Additionally, remove a redundant console.log statement in Chat.client.tsx and update the prompts documentation for clarity.

app/components/chat/Chat.client.tsx

@@ -249,8 +249,6 @@ export const ChatImpl = memo(
       });
     }, [messages, isLoading, parseMessages]);
 
-    console.log('messages', messages);
-
     const scrollTextArea = () => {
       const textarea = textareaRef.current;