Migrate vibecoding examples from React-Markdown to Streamdown (#1307)

### Description

This pull request refactors the rendering of markdown-like content
across both the Vibe Coding Platform and Python IDE frontend by
replacing all usages of `react-markdown` (and related plugins) with the
new `Streamdown` component. This change streamlines markdown rendering,
removes custom renderer code, and updates dependencies accordingly.

**Rendering changes:**

* Replaced all instances of `MarkdownRenderer` and `react-markdown` with
the `Streamdown` component in chat message components, including
`reasoning.tsx`, `report-errors.tsx`, `run-command.tsx`, `text.tsx`, and
the Python IDE's `ChatTimeline`. This ensures consistent markdown
rendering using `Streamdown` throughout the application.
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* Removed the custom `MarkdownRenderer` component and its associated
code, as it is no longer needed with the adoption of `Streamdown`.

**Dependency and configuration updates:**

* Updated `package.json` files to remove `react-markdown`, `remark-gfm`,
and `rehype-raw` dependencies and add `streamdown` as a new dependency
for both projects.
[[1]](diffhunk://#diff-3c8075b8a95131416e3856c63c1c28bdb94a30f320b0065b2ce9586e91168dccL40-L45)
[[2]](diffhunk://#diff-76ef8e0a9755e6f1a85dd18d222ac6ace40e838e7f21a552e2b1592247946ab1L25-R25)

* Updated Tailwind and build configuration files to include
`streamdown`'s distribution files for proper styling and integration.
[[1]](diffhunk://#diff-72477083d1a4198c17e7ca54cf97560fc108079f3ea55004730eb5fb99367d6cR3)
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### Demo URL

Awaiting preview deploy.

### Type of Change

- [ ] New Example
- [x] Example updates (Bug fixes, new features, etc.)
- [ ] Other (changes to the codebase, but not to examples)

Author: haydenbleasel

apps/vibe-coding-platform/app/globals.css

@@ -1,5 +1,6 @@
 @import 'tailwindcss';
 @import 'tw-animate-css';
+@source "../node_modules/streamdown/dist/*.js";
 
 :root {
   --background: rgb(255, 255, 255);

apps/vibe-coding-platform/components/chat/message-part/reasoning.tsx

@@ -1,7 +1,7 @@
 import type { ReasoningUIPart } from 'ai'
-import { MarkdownRenderer } from '@/components/markdown-renderer/markdown-renderer'
 import { MessageSpinner } from '../message-spinner'
 import { useReasoningContext } from '../message'
+import { Streamdown } from 'streamdown'
 
 export function Reasoning({
   part,
@@ -37,7 +37,7 @@ export function Reasoning({
       <div className="px-3 py-2">
         <div className="text-secondary-foreground font-mono leading-normal">
           {isExpanded || !hasMoreContent ? (
-            <MarkdownRenderer content={text} />
+            <Streamdown>{text}</Streamdown>
           ) : (
             <div className="overflow-hidden">{firstLine}</div>
           )}

apps/vibe-coding-platform/components/chat/message-part/report-errors.tsx

@@ -2,7 +2,7 @@ import type { DataPart } from '@/ai/messages/data-parts'
 import { BugIcon } from 'lucide-react'
 import { ToolHeader } from '../tool-header'
 import { ToolMessage } from '../tool-message'
-import Markdown from 'react-markdown'
+import { Streamdown } from 'streamdown'
 
 export function ReportErrors({
   message,
@@ -16,7 +16,7 @@ export function ReportErrors({
         <span>Auto-detected errors</span>
       </ToolHeader>
       <div className="relative min-h-5">
-        <Markdown>{message.summary}</Markdown>
+        <Streamdown>{message.summary}</Streamdown>
       </div>
     </ToolMessage>
   )

apps/vibe-coding-platform/components/chat/message-part/run-command.tsx

@@ -3,7 +3,7 @@ import { CheckIcon, SquareChevronRightIcon, XIcon } from 'lucide-react'
 import { Spinner } from './spinner'
 import { ToolHeader } from '../tool-header'
 import { ToolMessage } from '../tool-message'
-import Markdown from 'react-markdown'
+import { Streamdown } from 'streamdown'
 
 export function RunCommand({ message }: { message: DataPart['run-command'] }) {
   return (
@@ -29,9 +29,9 @@ export function RunCommand({ message }: { message: DataPart['run-command'] }) {
             <CheckIcon className="w-4 h-4" />
           )}
         </Spinner>
-        <Markdown>{`\`${message.command} ${message.args.join(
+        <Streamdown>{`\`${message.command} ${message.args.join(
           ' '
-        )}\``}</Markdown>
+        )}\``}</Streamdown>
       </div>
     </ToolMessage>
   )

apps/vibe-coding-platform/components/chat/message-part/text.tsx

@@ -1,10 +1,10 @@
 import type { TextUIPart } from 'ai'
-import { MarkdownRenderer } from '@/components/markdown-renderer/markdown-renderer'
+import { Streamdown } from 'streamdown'
 
 export function Text({ part }: { part: TextUIPart }) {
   return (
     <div className="text-sm px-3.5 py-3 border bg-secondary/90 text-secondary-foreground border-gray-300 rounded-md font-mono">
-      <MarkdownRenderer content={part.text} />
+      <Streamdown>{part.text}</Streamdown>
     </div>
   )
 }

apps/vibe-coding-platform/components/markdown-renderer/markdown-renderer.tsx

@@ -37,12 +37,10 @@
     "nuqs": "2.4.3",
     "react": "19.1.0",
     "react-dom": "19.1.0",
-    "react-markdown": "10.1.0",
+    "streamdown": "^1.6.6",
     "react-resizable-panels": "3.0.4",
     "react-spinners": "0.17.0",
     "react-syntax-highlighter": "15.6.1",
-    "rehype-raw": "7.0.0",
-    "remark-gfm": "4.0.1",
     "sonner": "^2.0.6",
     "strip-ansi": "7.1.0",
     "swr": "2.3.4",