feat: 优化大厅 Jackpot 参与提示与玩家页头布局

src/features/hall/hall-bet-preview-dialog.tsx

@@ -31,6 +31,7 @@ type HallBetPreviewDialogProps = {
   currencyCode: string;
   data: TicketPreviewData | null;
   placing: boolean;
+  jackpotEnabled?: boolean;
   /** 界面 §4.2：封盘后禁止提交，主按钮文案为「已封盘」 */
   allowSubmit?: boolean;
   onConfirmPlace: () => void;
@@ -107,6 +108,7 @@ export function HallBetPreviewDialog({
   currencyCode,
   data,
   placing,
+  jackpotEnabled = false,
   allowSubmit = true,
   onConfirmPlace,
 }: HallBetPreviewDialogProps) {
@@ -188,6 +190,16 @@ export function HallBetPreviewDialog({
                   </span>
                 </div>
 
+                {jackpotEnabled ? (
+                  <Alert className="border-[#d9ecff] bg-[#f4f9ff] text-[#0b3f96]">
+                    <CheckCircle2 className="size-4" />
+                    <AlertTitle>{t("hall.jackpotParticipation.title")}</AlertTitle>
+                    <AlertDescription className="text-xs leading-relaxed">
+                      {t("hall.jackpotParticipation.previewDescription")}
+                    </AlertDescription>
+                  </Alert>
+                ) : null}
+
                 <div className="overflow-x-auto rounded-xl border border-[#dfe8f6]">
                   <table className="min-w-[640px] w-full border-collapse text-xs">
                     <thead className="bg-[#f4f7fd] text-[#304f86]">