feat: add TextShimmerLoader component for enhanced loading states

- Introduced a new TextShimmerLoader component to provide a shimmer effect for loading text, improving user experience during in-progress states.
- Updated the TodoItem component to utilize the TextShimmerLoader for displaying labels of in-progress tasks, replacing the previous pulse animation.

surfsense_web/components/prompt-kit/loader.tsx

@@ -0,0 +1,74 @@
+"use client";
+
+import { cn } from "@/lib/utils";
+
+export interface LoaderProps {
+  variant?: "text-shimmer";
+  size?: "sm" | "md" | "lg";
+  text?: string;
+  className?: string;
+}
+
+const textSizes = {
+  sm: "text-xs",
+  md: "text-sm",
+  lg: "text-base",
+} as const;
+
+/**
+ * TextShimmerLoader - A text loader with a shimmer gradient animation
+ * Used for in-progress states in write_todos and chain-of-thought
+ */
+export function TextShimmerLoader({
+  text = "Thinking",
+  className,
+  size = "md",
+}: {
+  text?: string;
+  className?: string;
+  size?: "sm" | "md" | "lg";
+}) {
+  return (
+    <>
+      <style>
+        {`
+          @keyframes shimmer {
+            0% { background-position: 200% 50%; }
+            100% { background-position: -200% 50%; }
+          }
+        `}
+      </style>
+      <span
+        className={cn(
+          "bg-[linear-gradient(to_right,var(--muted-foreground)_40%,var(--foreground)_60%,var(--muted-foreground)_80%)]",
+          "bg-[length:200%_auto] bg-clip-text font-medium text-transparent",
+          "animate-[shimmer_4s_infinite_linear]",
+          textSizes[size],
+          className
+        )}
+      >
+        {text}
+      </span>
+    </>
+  );
+}
+
+/**
+ * Loader component - currently only supports text-shimmer variant
+ * Can be extended with more variants if needed in the future
+ */
+export function Loader({
+  variant = "text-shimmer",
+  size = "md",
+  text,
+  className,
+}: LoaderProps) {
+  switch (variant) {
+    case "text-shimmer":
+    default:
+      return (
+        <TextShimmerLoader text={text} size={size} className={className} />
+      );
+  }
+}
+

surfsense_web/components/tool-ui/plan/plan.tsx

@@ -7,7 +7,7 @@ import {
   PartyPopper,
   XCircle,
 } from "lucide-react";
-import type { FC, ReactNode } from "react";
+import type { FC } from "react";
 import { useMemo, useState } from "react";
 import {
   Accordion,
@@ -18,6 +18,7 @@ import {
 import { Button } from "@/components/ui/button";
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
 import { Collapsible, CollapsibleContent, CollapsibleTrigger } from "@/components/ui/collapsible";
+import { TextShimmerLoader } from "@/components/prompt-kit/loader";
 import { Progress } from "@/components/ui/progress";
 import { cn } from "@/lib/utils";
 import type { Action, ActionsConfig } from "../shared/schema";
@@ -73,24 +74,33 @@ interface TodoItemProps {
 
 const TodoItem: FC<TodoItemProps> = ({ todo, isStreaming = true }) => {
   const isStrikethrough = todo.status === "completed" || todo.status === "cancelled";
-  // Only show pulse animation if streaming and in progress
+  // Only show shimmer animation if streaming and in progress
   const isShimmer = todo.status === "in_progress" && isStreaming;
 
+  // Render the label with optional shimmer effect
+  const renderLabel = () => {
+    if (isShimmer) {
+      return <TextShimmerLoader text={todo.label} size="md" />;
+    }
+    return (
+      <span
+        className={cn(
+          "text-sm",
+          isStrikethrough && "line-through text-muted-foreground"
+        )}
+      >
+        {todo.label}
+      </span>
+    );
+  };
+
   if (todo.description) {
     return (
       <AccordionItem value={todo.id} className="border-0">
         <AccordionTrigger className="py-2 hover:no-underline">
           <div className="flex items-center gap-2">
             <StatusIcon status={todo.status} isStreaming={isStreaming} />
-            <span
-              className={cn(
-                "text-sm text-left",
-                isStrikethrough && "line-through text-muted-foreground",
-                isShimmer && "animate-pulse"
-              )}
-            >
-              {todo.label}
-            </span>
+            {renderLabel()}
           </div>
         </AccordionTrigger>
         <AccordionContent className="pb-2 pl-6">
@@ -103,15 +113,7 @@ const TodoItem: FC<TodoItemProps> = ({ todo, isStreaming = true }) => {
   return (
     <div className="flex items-center gap-2 py-2">
       <StatusIcon status={todo.status} isStreaming={isStreaming} />
-      <span
-        className={cn(
-          "text-sm",
-          isStrikethrough && "line-through text-muted-foreground",
-          isShimmer && "animate-pulse"
-        )}
-      >
-        {todo.label}
-      </span>
+      {renderLabel()}
     </div>
   );
 };