feat(design): 支付渠道 switch 原型 + segswitch 原子 + 图标/语言同源闸

- .segswitch 段控原子入 atoms.css + 登记 index.html
- purchase/ui-mobile/ui-desktop 三屏:购买页支付渠道 switch(USDT→crypto 默认 / 人民币→alipay),套餐价随渠道分币种显示,删两步弹层 + nezha
- 订单列表/详情集成进移动+桌面主框架
- icons.js 58 图标 sprite 单源 + gen_flutter_icons codegen + check-l1-sync 同源闸(图标同集 + l10n 完整)
- pay-v2 开发决策日志 docs/pay-v2-dev-log.md

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

design/codegen/gen_flutter_icons.mjs

@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+// gen_flutter_icons.mjs —— 图标单源 codegen（ds-flow step 2a）。
+// 图标真源 = design/prototype/icons.js（Lucide sprite）。读其 key 集，kebab→camel，
+// 生成 client/lib/widgets/pangolin_icons.dart（每个 sprite key 一行 static const）。
+// 零依赖（Node fs）。运行：node design/codegen/gen_flutter_icons.mjs
+import { readFileSync, writeFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import { dirname, resolve } from 'node:path';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const root = resolve(__dirname, '..', '..');
+const SPRITE = resolve(root, 'design/prototype/icons.js');
+const OUT = resolve(root, 'client/lib/widgets/pangolin_icons.dart');
+
+const src = readFileSync(SPRITE, 'utf8');
+// 抽 key：形如  'kebab-name': '<...
+const keys = [];
+const re = /'([a-z0-9-]+)'\s*:\s*'</g;
+let m;
+while ((m = re.exec(src)) !== null) keys.push(m[1]);
+if (keys.length === 0) { console.error('no icon keys found in', SPRITE); process.exit(1); }
+// 去重、稳定顺序（保留 sprite 出现次序）
+const seen = new Set();
+const ordered = keys.filter((k) => (seen.has(k) ? false : (seen.add(k), true)));
+
+const camel = (k) => k.replace(/-([a-z0-9])/g, (_, c) => c.toUpperCase());
+
+const lines = ordered.map((k) => {
+  const c = camel(k);
+  return `  static const ${c} = LucideIcons.${c};`;
+});
+
+const out = `// GENERATED by design/codegen/gen_flutter_icons.mjs —— 勿手改；图标真源=design/prototype/icons.js
+// 重新生成：node design/codegen/gen_flutter_icons.mjs
+import 'package:lucide_icons_flutter/lucide_icons.dart';
+
+class PangolinIcons {
+  PangolinIcons._();
+
+${lines.join('\n')}
+}
+`;
+
+writeFileSync(OUT, out);
+console.log(`generated ${OUT} (${ordered.length} icons)`);