fix(frontend): add X-Accel-Buffering to sse stream and optimize textarea input height resize

vibn-frontend/app/api/projects/[projectId]/stream/route.ts

@@ -72,6 +72,7 @@ export async function GET(
       "Content-Type": "text/event-stream",
       "Cache-Control": "no-cache, no-transform",
       Connection: "keep-alive",
+      "X-Accel-Buffering": "no",
     },
   });
 }

vibn-frontend/components/vibn-chat/chat-panel.tsx

@@ -2025,8 +2025,13 @@ export function ChatPanel({
                 }}
                 onInput={(e) => {
                   const el = e.currentTarget;
+                  const newlines = (el.value.match(/\n/g) || []).length;
+                  // Cache lastNewlines on the DOM element to avoid state re-render lag
+                  if ((el as any).lastNewlines !== newlines) {
+                    (el as any).lastNewlines = newlines;
                     el.style.height = "auto";
                     el.style.height = Math.min(el.scrollHeight, 120) + "px";
+                  }
                 }}
               />
               {selectToggle}