fix(desktop): compact streamdown h1 rendering

Render top-level Streamdown headings as h3-sized text while keeping them above body copy.

Author: ComputelessComputer

apps/desktop/src/session/components/streamdown.tsx

@@ -6,9 +6,9 @@ const HEADING_WITH_MARGIN = "mt-4 first:mt-0";
 
 export const streamdownComponents = {
   h1: (props: React.HTMLAttributes<HTMLHeadingElement>) => (
-    <h1 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-xl"])}>
+    <h3 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-base"])}>
       {props.children as React.ReactNode}
-    </h1>
+    </h3>
   ),
   h2: (props: React.HTMLAttributes<HTMLHeadingElement>) => (
     <h2 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-lg"])}>

packages/tiptap/src/shared/streamdown-components.tsx

@@ -7,9 +7,9 @@ const HEADING_WITH_MARGIN = "mt-4 first:mt-0";
 
 export const streamdownComponents = {
   h1: (props: React.HTMLAttributes<HTMLHeadingElement>) => (
-    <h1 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-xl"])}>
+    <h3 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-base"])}>
       {props.children as React.ReactNode}
-    </h1>
+    </h3>
   ),
   h2: (props: React.HTMLAttributes<HTMLHeadingElement>) => (
     <h2 className={cn([HEADING_SHARED, HEADING_WITH_MARGIN, "text-lg"])}>