Add read-only production runtime audit

apps/web/app/api/chat/route.ts

@@ -227,11 +227,13 @@ function toCitations(raw: RagCitation[]): Citation[] {
 export async function POST(request: Request) {
   let content: string;
   let conversationId: string | null = null;
+  let responseMode: "ai" | "monograph" = "ai";
   try {
     const body = await request.json();
     content = typeof body?.content === "string" ? body.content.trim() : "";
     conversationId =
       typeof body?.conversationId === "string" ? body.conversationId : null;
+    responseMode = body?.responseMode === "monograph" ? "monograph" : "ai";
   } catch {
     return NextResponse.json({ error: "invalid_body" }, { status: 400 });
   }
@@ -277,6 +279,7 @@ export async function POST(request: Request) {
         subject_scope: "human",
         intent: "fact_lookup",
         conversation_id: conversationId,
+        response_mode: responseMode,
       }),
       cache: "no-store",
       // Propagate a browser disconnect/Stop action to the upstream fetch.