重构(平台入口): 平台侧与 AGC 壳改用三池余额，退役 legacy 总额写入通道

- 平台入口与钱包 store 不再从充值中心响应读 walletBalance，合计改为按三池派生
- AGC 账户钱包同步：只透传 mudPointBalance，删掉 RechargeContent 的 walletBalance 排除项
- 删除已无生产调用方的 applyLegacyWalletBalanceSnapshot 与对应测试；明细读取失败不再伪造「只有总额」的中间态
- 图片编辑器与平台入口测试 fixture 改为三池形状，钱包面板断言改用「永久泥点 / 月度泥点」

Co-authored-by: Junie <junie@jetbrains.com>

src/components/platform-entry/PlatformEntryActiveFlowShell.tsx

@@ -22,6 +22,7 @@ import { PlatformProfileRechargeModal } from '../../../packages/shared/src/compo
 import { PlatformProfileReferralModal } from '../../../packages/shared/src/components/PlatformProfileReferralModal';
 import { PlatformProfileWalletLedgerModal } from '../../../packages/shared/src/components/PlatformProfileWalletLedgerModal';
 import type { ProfileDashboardSummary } from '../../../packages/shared/src/contracts/runtime';
+import { resolveProfileMudPointDisplayTotal } from '../../../packages/shared/src/utils/mudPoints';
 import {
   hasAppHistoryBackEntry,
   pushAppHistoryPath,
@@ -376,7 +377,9 @@ export function PlatformEntryFlowShellImpl({
   });
   const legacyWalletBalance = walletOwnerMatchesCurrentUser
     ? (storedLegacyWalletBalance ??
-      profileCenter.rechargeCenter?.walletBalance ??
+      resolveProfileMudPointDisplayTotal(
+        profileCenter.rechargeCenter?.mudPointBalance,
+      ) ??
       null)
     : null;