fix: simplify conversion composer hints

web/components/ad-recreation-board.tsx

@@ -4139,7 +4139,7 @@ function SourceSubjectPipeline({
                 </div>
               )) : (
                 <div className="flex h-full min-h-[74px] items-center justify-center px-2 text-center text-[10px] leading-snug text-white/30">
-                  直接发送复刻、创新、卡通、数量和画面要求。
+                  点亮要保留的识别元素；需要变化时直接补充要求。
                 </div>
               )}
             </div>
@@ -4147,7 +4147,7 @@ function SourceSubjectPipeline({
               <textarea
                 value={agentInput}
                 onChange={(event) => setAgentInput(event.target.value)}
-                placeholder="直接描述：复刻这个人、参考创意换人物、卡通风格、人物占画面90%..."
+                placeholder="补充你想调整的点；不写则按已选保留元素和当前张数生成。"
                 className="h-[72px] w-full resize-none rounded border border-transparent bg-transparent px-1 py-1 text-[10.5px] leading-snug text-white outline-none transition placeholder:text-white/24 focus:border-cyan-200/45"
               />
               <div className="mt-1 flex items-center gap-1.5">