chore: sync local updates

mengyaconnect-backend/build-linux.ps1

@@ -0,0 +1,12 @@
+$ErrorActionPreference = "Stop"
+Set-Location $PSScriptRoot
+New-Item -ItemType Directory -Force -Path dist | Out-Null
+$env:CGO_ENABLED = "0"
+$env:GOOS = "linux"
+$env:GOARCH = "amd64"
+$out = Join-Path $PSScriptRoot "dist\mengyaconnect-backend"
+go build -trimpath -ldflags="-s -w" -o $out .
+$b = [IO.File]::ReadAllBytes($out)
+if ($b.Length -ge 4 -and $b[0] -eq 0x7F -and $b[1] -eq 0x45) { Write-Host "OK: Linux ELF amd64 -> $out" }
+elseif ($b[0] -eq 0x4D -and $b[1] -eq 0x5A) { throw "Got Windows PE — check go env" }
+else { throw "Unknown output format" }