fix(ci): ISCC 调用关闭 MSYS 参数路径转换，修复 more than one script filename

Git Bash(MSYS) 把 /D 开头的参数当 POSIX 路径自动转换，导致 ISCC 的
/DAppVer /DSrcDir /DOutDir 丢失 /D 前缀、被当成多个脚本文件名而报错。
调用 ISCC 时设 MSYS_NO_PATHCONV=1 + MSYS2_ARG_CONV_EXCL='*' 关闭转换。
install-innosetup.ps1 顺带加 /LOG 失败时打印安装日志。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/ci/compile-windows.sh

@@ -60,7 +60,10 @@ fi
 cp deploy/windows/jiu-installer.iss "${BUILD_ROOT}/jiu-installer.iss"
 mkdir -p "${BUILD_ROOT}/dist"
 echo "==> building installer with Inno Setup (version ${VER})"
-"$ISCC" \
+# MSYS_NO_PATHCONV / MSYS2_ARG_CONV_EXCL disable Git Bash's automatic conversion
+# of /-leading args into Windows paths, which otherwise mangles ISCC's /D defines
+# (turning them into extra "script filenames").
+MSYS_NO_PATHCONV=1 MSYS2_ARG_CONV_EXCL='*' "$ISCC" \
   "/DAppVer=${VER}" \
   "/DSrcDir=C:\\jiu-build\\client\\build\\windows\\x64\\runner\\Release" \
   "/DOutDir=C:\\jiu-build\\dist" \

scripts/ci/install-innosetup.ps1

@@ -23,9 +23,14 @@ Write-Output "Downloaded $size bytes"
 if ($size -lt 1000000) { throw "Downloaded file too small ($size bytes) - not a valid installer" }
 
 Write-Output "Installing silently..."
-$p = Start-Process -FilePath $out -ArgumentList '/VERYSILENT','/SUPPRESSMSGBOXES','/NORESTART','/SP-','/NOICONS' -Wait -PassThru
+$log = Join-Path $env:TEMP 'innosetup-install.log'
+$p = Start-Process -FilePath $out -ArgumentList '/VERYSILENT','/SUPPRESSMSGBOXES','/NORESTART','/SP-','/NOICONS',"/LOG=$log" -Wait -PassThru
 Write-Output "Installer exit code: $($p.ExitCode)"
-if ($p.ExitCode -ne 0) { throw "Inno Setup installer failed with exit code $($p.ExitCode)" }
+if ($p.ExitCode -ne 0) {
+  Write-Output "----- install log tail -----"
+  if (Test-Path $log) { Get-Content $log -Tail 40 | ForEach-Object { Write-Output $_ } }
+  throw "Inno Setup installer failed with exit code $($p.ExitCode)"
+}
 
 foreach ($c in $candidates) {
   if (Test-Path $c) { Write-Output "ISCC installed: $c"; exit 0 }