docs(agent): annotate stream invariants

src/media/parse.ts

@@ -27,6 +27,8 @@ export function splitMediaFromOutput(raw: string): {
   mediaUrls?: string[];
   mediaUrl?: string; // legacy first item for backward compatibility
 } {
+  // KNOWN: Leading whitespace is semantically meaningful in Markdown (lists, indented fences).
+  // We only trim the end; token cleanup below handles removing `MEDIA:` lines.
   const trimmedRaw = raw.trimEnd();
   if (!trimmedRaw.trim()) return { text: "" };