Gate 1 integration: shared streamdown config in reasoning, teaserText flattens \(...\)

components/ai-elements/message.tsx

@@ -346,7 +346,7 @@ export type MessageResponseProps = ComponentProps<typeof Streamdown>;
 //
 // mermaid: the plugin supplies the renderer; the `mermaid` PROP (below)
 // carries the dark theme + the error fallback component.
-const streamdownPlugins = {
+export const streamdownPlugins = {
   cjk: {
     ...cjk,
     remarkPluginsAfter: [...cjk.remarkPluginsAfter, remarkBreaks],
@@ -364,7 +364,7 @@ const mermaidTheme: MermaidConfig = {
   theme: "dark",
 };
 
-const mermaidOptions: MermaidOptions = {
+export const mermaidOptions: MermaidOptions = {
   config: mermaidTheme,
   errorComponent: MermaidError,
 };

components/ai-elements/reasoning.tsx

@@ -7,10 +7,6 @@ import {
   CollapsibleTrigger,
 } from "@/components/ui/collapsible";
 import { cn } from "@/lib/utils";
-import { cjk } from "@streamdown/cjk";
-import { code } from "@streamdown/code";
-import { createMathPlugin } from "@streamdown/math";
-import { mermaid } from "@streamdown/mermaid";
 import { BrainIcon, ChevronDownIcon } from "lucide-react";
 import type { ComponentProps, ReactNode } from "react";
 import {
@@ -23,8 +19,10 @@ import {
   useRef,
   useState,
 } from "react";
-import { Streamdown, type PluginConfig } from "streamdown";
+import { Streamdown } from "streamdown";
 
+import { transformMathDelimiters } from "@/src/core/math-delims";
+import { mermaidOptions, streamdownPlugins } from "./message";
 import { Shimmer } from "./shimmer";
 
 interface ReasoningContextValue {
@@ -204,13 +202,8 @@ export type ReasoningContentProps = ComponentProps<
   children: string;
 };
 
-// See message.tsx — same streamdown plugin type skew + math config.
+// Shares message.tsx's Streamdown config (math delimiters, dark mermaid,
-const streamdownPlugins = {
+// remark-breaks) — reasoning renders the same contract as message text.
-  cjk,
-  code,
-  math: createMathPlugin({ singleDollarTextMath: true }),
-  mermaid,
-} as unknown as PluginConfig;
 
 export const ReasoningContent = memo(
   ({ className, children, ...props }: ReasoningContentProps) => (
@@ -222,7 +215,9 @@ export const ReasoningContent = memo(
       )}
       {...props}
     >
-      <Streamdown plugins={streamdownPlugins}>{children}</Streamdown>
+      <Streamdown mermaid={mermaidOptions} plugins={streamdownPlugins}>
+        {transformMathDelimiters(children)}
+      </Streamdown>
     </CollapsibleContent>
   )
 );

components/question-dock.tsx

@@ -60,7 +60,9 @@ export function QuestionDock({ toolName, toolCallId, input, expanded, onExpand,
 /** A plain-text teaser of a question for the collapsed bar: unwrap math, flatten common LaTeX. */
 function teaserText(q: string): string {
 	return q
-		.replace(/\$\$?([^$]*)\$\$?/g, "$1")
+		.replace(/\\\(([\s\S]*?)\\\)/g, "$1") // \(...\) inline math
+		.replace(/\\\[([\s\S]*?)\\\]/g, "$1") // \[...\] display math
+		.replace(/\$\$?([^$]*)\$\$?/g, "$1") // legacy $...$ (pre-switch sessions)
 		.replace(/\\frac\{([^{}]*)\}\{([^{}]*)\}/g, "$1/$2")
 		.replace(/\\([a-zA-Z]+)/g, "$1")
 		.replace(/[{}]/g, "")