fix: ensure runtime env var reading for configurable headline

- Convert chat pages to async server components so process.env reads
  happen at runtime instead of build time
- Add force-dynamic to all routes reading env vars
- Use nullish coalescing (??) instead of logical OR (||) for headline
  fallback to allow intentionally empty strings

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Optimus (AI Agent) <agent@fulcria.com>

Author: optimus-fulcria

ui/src/app/agents/[namespace]/[name]/chat/[chatId]/page.tsx

@@ -1,9 +1,9 @@
-"use client";
-import { use } from "react";
 import ChatInterface from "@/components/chat/ChatInterface";
 
-export default function ChatPageView({ params }: { params: Promise<{ name: string; namespace: string; chatId: string }> }) {
-  const { name, namespace, chatId } = use(params);
+export const dynamic = "force-dynamic";
+
+export default async function ChatPageView({ params }: { params: Promise<{ name: string; namespace: string; chatId: string }> }) {
+  const { name, namespace, chatId } = await params;
 
   return <ChatInterface
     selectedAgentName={name}

ui/src/app/agents/[namespace]/[name]/chat/page.tsx

@@ -1,9 +1,10 @@
 import ChatInterface from "@/components/chat/ChatInterface";
-import { use } from 'react';
+
+export const dynamic = "force-dynamic";
 
 // This page component receives props (like params) from the Layout
-export default function ChatAgentPage({ params }: { params: Promise<{ name: string, namespace: string }> }) {
-  const { name, namespace } = use(params);
+export default async function ChatAgentPage({ params }: { params: Promise<{ name: string, namespace: string }> }) {
+  const { name, namespace } = await params;
   const headline = process.env.NEXT_PUBLIC_HEADLINE;
   return <ChatInterface selectedAgentName={name} selectedNamespace={namespace} headline={headline} />;
 }

ui/src/components/chat/ChatInterface.tsx

@@ -627,7 +627,7 @@ export default function ChatInterface({ selectedAgentName, selectedNamespace, se
             ) : storedMessages.length === 0 && streamingMessages.length === 0 && !isStreaming ? (
               <div className="flex items-center justify-center h-full min-h-[50vh]">
                 <div className="bg-card p-6 rounded-lg shadow-sm border max-w-md text-center">
-                  <h3 className="text-lg font-medium mb-2">{headline || "Start a conversation"}</h3>
+                  <h3 className="text-lg font-medium mb-2">{headline ?? "Start a conversation"}</h3>
                   <p className="text-muted-foreground">
                     To begin chatting with the agent, type your message in the input box below.
                   </p>