init: 初始化 AssetX 项目仓库

包含 webapp（Next.js 用户端）、webapp-back（Go 后端）、
antdesign（管理后台）、landingpage（营销落地页）、
数据库 SQL 和配置文件。

webapp/components/common/TokenSelector.tsx

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+"use client";
+
+import { useEffect, useRef } from "react";
+import Image from "next/image";
+import {
+  Dropdown,
+  DropdownTrigger,
+  DropdownMenu,
+  DropdownItem,
+} from "@heroui/react";
+import { useTokenList } from "@/hooks/useTokenList";
+import { Token } from "@/lib/api/tokens";
+
+interface TokenSelectorProps {
+  selectedToken?: Token;
+  onSelect: (token: Token) => void;
+  filterTypes?: ('stablecoin' | 'yield-token')[];
+  disabled?: boolean;
+  defaultSymbol?: string;
+}
+
+export default function TokenSelector({
+  selectedToken,
+  onSelect,
+  filterTypes = ['stablecoin', 'yield-token'],
+  disabled = false,
+  defaultSymbol,
+}: TokenSelectorProps) {
+  const hasInitialized = useRef(false);
+
+  const { tokens: allTokens, isLoading } = useTokenList();
+  const tokens = allTokens.filter(t => filterTypes.includes(t.tokenType));
+
+  // 数据加载完成后自动选中默认 token（仅初始化一次）
+  useEffect(() => {
+    if (hasInitialized.current || selectedToken || tokens.length === 0) return;
+    hasInitialized.current = true;
+    const target = defaultSymbol
+      ? (tokens.find(t => t.symbol === defaultSymbol) ?? tokens[0])
+      : tokens[0];
+    onSelect(target);
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [tokens]);
+
+  if (isLoading) {
+    return (
+      <button className="bg-white dark:bg-gray-700 rounded-full border border-gray-400 dark:border-gray-500 px-4 h-[46px] flex items-center gap-2 opacity-50 cursor-not-allowed">
+        <div className="w-8 h-8 rounded-full bg-gray-200 dark:bg-gray-600 animate-pulse" />
+        <span className="text-body-default font-bold text-text-primary dark:text-white">
+          Loading...
+        </span>
+      </button>
+    );
+  }
+
+  return (
+    <Dropdown shouldBlockScroll={false}>
+      <DropdownTrigger>
+        <button
+          disabled={disabled}
+          className={`bg-white dark:bg-gray-700 rounded-full border border-gray-400 dark:border-gray-500 px-4 h-[46px] flex items-center justify-between gap-2 outline-none focus:outline-none transition-all duration-200 ease-in-out ${
+            disabled ? 'opacity-50 cursor-not-allowed' : 'hover:border-primary dark:hover:border-primary-dark hover:shadow-md'
+          }`}
+        >
+          {selectedToken ? (
+            <>
+              <div className="flex items-center gap-2">
+                <Image
+                  src={selectedToken.iconUrl || '/assets/tokens/default.svg'}
+                  alt={selectedToken.symbol}
+                  width={32}
+                  height={32}
+                  className="rounded-full transition-opacity duration-150"
+                  priority
+                  onError={(e) => {
+                    (e.target as HTMLImageElement).src = '/assets/tokens/default.svg';
+                  }}
+                />
+                <span className="text-body-default font-bold text-text-primary dark:text-white transition-opacity duration-150">
+                  {selectedToken.symbol}
+                </span>
+              </div>
+              <svg
+                className="w-4 h-4 text-text-tertiary dark:text-gray-400"
+                fill="none"
+                viewBox="0 0 24 24"
+                stroke="currentColor"
+              >
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
+              </svg>
+            </>
+          ) : (
+            <span className="text-body-default text-text-tertiary dark:text-gray-400">
+              No tokens available
+            </span>
+          )}
+        </button>
+      </DropdownTrigger>
+      <DropdownMenu
+        aria-label="Token selection"
+        onAction={(key) => {
+          const token = tokens.find(t => t.symbol === key);
+          if (token) onSelect(token);
+        }}
+      >
+        {tokens.map((token) => (
+          <DropdownItem
+            key={token.symbol}
+            className="hover:bg-bg-subtle dark:hover:bg-gray-700 rounded-lg"
+            textValue={token.symbol}
+          >
+            <div className="flex items-center gap-3 py-1">
+              <Image
+                src={token.iconUrl || '/assets/tokens/default.svg'}
+                alt={token.symbol || 'token'}
+                width={32}
+                height={32}
+                className="rounded-full"
+                onError={(e) => {
+                  (e.target as HTMLImageElement).src = '/assets/tokens/default.svg';
+                }}
+              />
+              <div className="flex flex-col">
+                <span className="text-body-default font-bold text-text-primary dark:text-white">
+                  {token.symbol}
+                </span>
+                <span className="text-caption-tiny text-text-tertiary dark:text-gray-400">
+                  {token.name}
+                </span>
+              </div>
+            </div>
+          </DropdownItem>
+        ))}
+      </DropdownMenu>
+    </Dropdown>
+  );
+}