improvement(ui): delegate streaming animation to Streamdown component

Remove custom useStreamingText hook and useThrottledValue indirection
in favor of Streamdown's built-in streaming props. This eliminates the
manual character-by-character reveal logic (setInterval, easing, chase
factor) and lets the library handle animation natively, reducing
complexity and improving consistency across Mothership and chat.

Author: emir-karabeg

apps/sim/app/chat/components/message/components/markdown-renderer.tsx

@@ -176,9 +176,11 @@ const DEFAULT_COMPONENTS = createCustomComponents(LinkWithPreview)
 const MarkdownRenderer = memo(function MarkdownRenderer({
   content,
   customLinkComponent,
+  isStreaming = false,
 }: {
   content: string
   customLinkComponent?: typeof LinkWithPreview
+  isStreaming?: boolean
 }) {
   const components = useMemo(() => {
     if (!customLinkComponent) {
@@ -191,7 +193,12 @@ const MarkdownRenderer = memo(function MarkdownRenderer({
 
   return (
     <div className='space-y-4 break-words font-sans text-[var(--landing-text)] text-base leading-relaxed'>
-      <Streamdown mode='static' components={components}>
+      <Streamdown
+        mode={isStreaming ? undefined : 'static'}
+        isAnimating={isStreaming}
+        animated={isStreaming}
+        components={components}
+      >
         {processedContent}
       </Streamdown>
     </div>

apps/sim/app/chat/components/message/message.tsx

@@ -8,7 +8,6 @@ import {
   ChatFileDownloadAll,
 } from '@/app/chat/components/message/components/file-download'
 import MarkdownRenderer from '@/app/chat/components/message/components/markdown-renderer'
-import { useThrottledValue } from '@/hooks/use-throttled-value'
 
 export interface ChatAttachment {
   id: string
@@ -39,9 +38,14 @@ export interface ChatMessage {
   files?: ChatFile[]
 }
 
-function EnhancedMarkdownRenderer({ content }: { content: string }) {
-  const throttled = useThrottledValue(content)
-  return <MarkdownRenderer content={throttled} />
+function EnhancedMarkdownRenderer({
+  content,
+  isStreaming,
+}: {
+  content: string
+  isStreaming?: boolean
+}) {
+  return <MarkdownRenderer content={content} isStreaming={isStreaming} />
 }
 
 export const ClientChatMessage = memo(
@@ -188,7 +192,10 @@ export const ClientChatMessage = memo(
                       {JSON.stringify(cleanTextContent, null, 2)}
                     </pre>
                   ) : (
-                    <EnhancedMarkdownRenderer content={cleanTextContent as string} />
+                    <EnhancedMarkdownRenderer
+                      content={cleanTextContent as string}
+                      isStreaming={message.isStreaming}
+                    />
                   )}
                 </div>
               </div>

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/chat-content/chat-content.tsx

@@ -18,7 +18,6 @@ import {
   SpecialTags,
 } from '@/app/workspace/[workspaceId]/home/components/message-content/components/special-tags'
 import type { MothershipResource } from '@/app/workspace/[workspaceId]/home/types'
-import { useStreamingText } from '@/hooks/use-streaming-text'
 
 const LANG_ALIASES: Record<string, string> = {
   js: 'javascript',
@@ -236,15 +235,13 @@ interface ChatContentProps {
   isStreaming?: boolean
   onOptionSelect?: (id: string) => void
   onWorkspaceResourceSelect?: (resource: MothershipResource) => void
-  smoothStreaming?: boolean
 }
 
 export function ChatContent({
   content,
   isStreaming = false,
   onOptionSelect,
   onWorkspaceResourceSelect,
-  smoothStreaming = true,
 }: ChatContentProps) {
   const hydratedStreamingRef = useRef(isStreaming && content.trim().length > 0)
   const previousIsStreamingRef = useRef(isStreaming)
@@ -270,9 +267,7 @@ export function ChatContent({
     return () => window.removeEventListener('wsres-click', handler)
   }, [])
 
-  const rendered = useStreamingText(content, isStreaming && smoothStreaming)
-
-  const parsed = useMemo(() => parseSpecialTags(rendered, isStreaming), [rendered, isStreaming])
+  const parsed = useMemo(() => parseSpecialTags(content, isStreaming), [content, isStreaming])
   const hasSpecialContent = parsed.hasPendingTag || parsed.segments.some((s) => s.type !== 'text')
 
   if (hasSpecialContent) {
@@ -349,7 +344,7 @@ export function ChatContent({
         animated={isStreaming && !hydratedStreamingRef.current}
         components={MARKDOWN_COMPONENTS}
       >
-        {rendered}
+        {content}
       </Streamdown>
     </div>
   )

apps/sim/app/workspace/[workspaceId]/home/components/message-content/message-content.tsx

@@ -374,7 +374,6 @@ export function MessageContent({
   const hasSubagentEnded = blocks.some((b) => b.type === 'subagent_end')
   const showTrailingThinking =
     isStreaming && !hasTrailingContent && (hasSubagentEnded || allLastGroupToolsDone)
-  const hasStructuredSegments = segments.some((segment) => segment.type !== 'text')
   const lastOpenSubagentGroupId = [...segments]
     .reverse()
     .find(
@@ -394,7 +393,6 @@ export function MessageContent({
                 isStreaming={isStreaming}
                 onOptionSelect={onOptionSelect}
                 onWorkspaceResourceSelect={onWorkspaceResourceSelect}
-                smoothStreaming={!hasStructuredSegments}
               />
             )
           case 'agent_group': {