fix: judge a declared slot by the platform's copy

--declared-only settled each slot on its first declaration before the
cores narrowed the list, and the declared event judged the core copy
served in its place. Both now read the declaration whose systems
remain, as the platform checks it.

install.ps1

@@ -11,7 +11,7 @@
 
     $ErrorActionPreference = "Stop"
     $defaultInstallUrl = "https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-    $defaultInstallSha256 = "b23c6da4ee131f898c25540bd53677ea4112964fd00b209e4fe85dfdba8427d1"
+    $defaultInstallSha256 = "5fedfbf308ba04a174ce0682380a28150b6fe5eab514a605e3b318193ce37c7a"
     $maximumInstallerBytes = 2MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }