fix(chat): surface PolicyDecision feedback on send failure

app/(order)/chat/[id]/page.tsx

@@ -11,6 +11,7 @@ import { Input } from "@/components/ui/input"
 import { ScrollArea } from "@/components/ui/scroll-area"
 import { sendImageMessage, sendTextMessage } from "@/lib/api/chat"
 import { cn } from "@/lib/utils"
+import { notifyInfo } from "@/lib/toast"
 import { useAuthStore } from "@/store/auth"
 import { useChatStore } from "@/store/chat"
 
@@ -146,7 +147,8 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
             onChange={(event) => {
               const file = event.target.files?.[0]
               if (!file) return
-              sendImageMessage(session.id, URL.createObjectURL(file))
+              const result = sendImageMessage(session.id, URL.createObjectURL(file))
+              if (result && !result.ok) notifyInfo(result.message ?? "发送失败")
               event.target.value = ""
             }}
           />
@@ -157,7 +159,11 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
               const text = input.trim()
               if (!text) return
 
-              sendTextMessage(session.id, text)
+              const result = sendTextMessage(session.id, text)
+              if (result && !result.ok) {
+                notifyInfo(result.message ?? "发送失败")
+                return
+              }
               setInput("")
             }}
           >