feat: mark each speaker with a role icon in the transcript (#5)

src/lib/markdown.ts

@@ -14,6 +14,16 @@ import type { ChatTurn, ThreadMessage } from "./types";
 
 export const STREAMING_CURSOR = "▍";
 
+/**
+ * Role markers for the transcript.
+ *
+ * Emoji rather than icon images: Vicinae's markdown renderer is minimal and
+ * there is no reliable way to inline an `icon://` reference into markdown, but
+ * plain text always renders.
+ */
+export const USER_MARKER = "👤";
+export const ASSISTANT_MARKER = "✨";
+
 /** Prefixes every line so a multi-line message stays one continuous quote block. */
 export function quote(text: string): string {
   return text
@@ -31,11 +41,11 @@ export function previewText(text: string, max: number): string {
 
 function renderMessage(message: ThreadMessage): string {
   if (message.role === "user") {
-    return `**You**\n\n${quote(message.text)}`;
+    return `${USER_MARKER} **You**\n\n${quote(message.text)}`;
   }
 
   const body = message.text.trim() || (message.isStreaming ? "_Thinking…_" : "_No response._");
-  const sections = ["**Lam**", "", message.isStreaming ? `${body} ${STREAMING_CURSOR}` : body];
+  const sections = [`${ASSISTANT_MARKER} **Lam**`, "", message.isStreaming ? `${body} ${STREAMING_CURSOR}` : body];
 
   if (message.error) {
     sections.push("", `**Error** — ${message.error}`);