refactor(windows scripts): remove BOM and improve UTF-8 handling

windows/tools/system-info.ps1

@@ -1,4 +1,4 @@
-<#
+<#
     LXS - System Infos (Windows)
     Description: Essential system monitoring and diagnostic views.
                  Read-only: nothing here changes the machine.
@@ -20,7 +20,10 @@ if ($LxsLibPath -and (Test-Path $LxsLibPath)) {
         Write-Error 'Failed to fetch lib/common.ps1'
         exit 1
     }
-    . ([scriptblock]::Create($LxsLibSource))
+    # The library ships with a UTF-8 BOM (Windows PowerShell 5.1 needs it to
+    # read the file as UTF-8); over HTTP that BOM arrives as a leading U+FEFF
+    # character, which the parser will not accept.
+    . ([scriptblock]::Create(($LxsLibSource -replace '^\uFEFF', '')))
 }
 
 $env:LXS_LOG_FILE = Join-Path (Get-LxsTempDir) 'lxs_system_infos.log'
@@ -63,7 +66,7 @@ function Show-LxsSystemInformation {
             ForEach-Object { "$($_.Name) (driver $($_.DriverVersion))" })
         if ($gpu.Count -gt 0) { Write-LxsField 'GPU' $gpu }
     } catch {
-        # Headless or restricted WMI — not worth failing the whole view.
+        # Headless or restricted WMI - not worth failing the whole view.
     }
 
     # Activation status. LicenseStatus 1 = licensed.
@@ -81,7 +84,7 @@ function Show-LxsSystemInformation {
                 6 { 'Extended grace' }
                 default { 'Unknown' }
             }
-            Write-LxsField 'Activation' "$state — $($lic[0].Name)"
+            Write-LxsField 'Activation' "$state - $($lic[0].Name)"
         }
     } catch {
         # SoftwareLicensingProduct is unavailable on some SKUs.
@@ -172,7 +175,7 @@ function Show-LxsEventLogs {
     Show-LxsBoxTop -Title 'SYSTEM LOGS' -Right 'LAST 50'
     Write-Host ''
     foreach ($logName in @('System', 'Application')) {
-        Write-Host "$($script:Cyan)$($script:Bold)$logName — errors and warnings$($script:NC)"
+        Write-Host "$($script:Cyan)$($script:Bold)$logName - errors and warnings$($script:NC)"
         try {
             $events = Get-WinEvent -FilterHashtable @{ LogName = $logName; Level = 1, 2, 3 } -MaxEvents 25 -ErrorAction Stop
             $events | Format-Table -AutoSize -Wrap `