feat: 内置虾盘云 + 设备指纹绑定 + Release 流水线

- 新增 portable/lib/{fingerprint,xiapan-client,bootstrap-xiapan}.mjs：
  跨平台设备指纹（Win USB/disk + Mac UUID + Linux machine-id + seed 兜底）
  生成 sk-uc-{fingerprint} 形式的虾盘云 apiKey，启动时 merge 到 openclaw.json
- Config.html 顶部新增「已绑定虾盘云」横幅：指纹来源 + Key + 余额 + 充值/解绑
- config-server 增加 /api/xiapan/{status,bind,unbind} 三个端点
- Electron app 在 whenReady 调 bootstrap，新增 sync-lib.js 让 build 前自动同步
- 锁 OpenClaw 版本到 2026.4.29（OPENCLAW_VERSION 单一来源）
- 删除死代码 portable/充值.html
- 新增 .github/workflows/release.yml：tag 触发，出 portable zip + Electron exe/dmg
- README 增加内置虾盘云说明 + 直接下载发行版指引

portable/setup.ps1

@@ -204,16 +204,21 @@ if ($AllPlatforms) {
 
 $packageJsonPath = Join-Path $coreDir "package.json"
 if (-not (Test-Path -Path $packageJsonPath -PathType Leaf)) {
-    $packageJson = @'
+    $openclawVersionFile = Join-Path $PSScriptRoot "..\OPENCLAW_VERSION"
+    $openclawVersion = "2026.4.29"
+    if (Test-Path -Path $openclawVersionFile -PathType Leaf) {
+        $openclawVersion = (Get-Content -Path $openclawVersionFile -Raw).Trim()
+    }
+    $packageJson = @"
 {
   "name": "u-claw-core",
   "version": "1.0.0",
   "private": true,
   "dependencies": {
-    "openclaw": "latest"
+    "openclaw": "$openclawVersion"
   }
 }
-'@
+"@
     $packageJson | Out-File -FilePath $packageJsonPath -Encoding utf8
 }