refactor: 完成全站国际化改造，统一多语言支持

此提交完成了全项目的国际化适配：
1. 新增多语言翻译文件与基础配置
2. 替换所有硬编码文本为i18n调用
3. 优化语言切换与文档语言同步逻辑
4. 重构部分业务逻辑以支持动态翻译
5. 移除过时代码与硬编码配置

src/features/results/jackpot-results-strip.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useEffect, useState } from "react";
+import { useTranslation } from "react-i18next";
 
 import { getJackpotSummary } from "@/api/jackpot";
 import { formatMinorAsCurrency } from "@/lib/money";
@@ -13,6 +14,7 @@ type JackpotResultsStripProps = {
 export function JackpotResultsStrip({
   currencyCode = "NPR",
 }: JackpotResultsStripProps) {
+  const { t } = useTranslation("player");
   const [minor, setMinor] = useState<number | null>(null);
   const [enabled, setEnabled] = useState(false);
 
@@ -44,7 +46,7 @@ export function JackpotResultsStrip({
   return (
     <div className="rounded-xl border border-amber-200 bg-gradient-to-r from-amber-100 via-white to-[#f8fbff] px-3 py-3 shadow-[0_8px_20px_rgba(180,83,9,0.08)]">
       <p className="text-[11px] font-black uppercase tracking-normal text-amber-700">
-        Jackpot
+        {t("results.jackpotLabel")}
       </p>
       <p className="font-mono text-lg font-black tabular-nums text-[#0b3f96]">
         {formatMinorAsCurrency(minor, currencyCode.toUpperCase())}