fix(release): upload Linux AppImage under feed x64 name

Prevent stale TTRPGPlayer-x64.AppImage on the updates host when
electron-builder leaves an x86_64 alias beside an older x64 file.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/ttrpg-release/prepare-release.ps1

@@ -367,20 +367,37 @@ function Copy-ReleaseArtifacts {
 
   $copied = 0
   foreach ($name in ($names | Sort-Object)) {
+    # Always publish Linux AppImage under feed/site name (x64), never leave x86_64 alias.
+    if ($name -match 'x86_64' -and $name -match '\.AppImage$') {
+      $canonical = $name -replace 'x86_64', 'x64'
+      if ($names.Contains($canonical)) {
+        continue
+      }
+      $name = $canonical
+    }
+
     $src = Join-Path $BuildReleaseDir $name
+    $destName = $name
     if (-not (Test-Path -LiteralPath $src)) {
       if ($name -match 'x64' -and $name -notmatch 'x86_64') {
         $alt = $name -replace 'x64', 'x86_64'
-        $src = Join-Path $BuildReleaseDir $alt
+        $altPath = Join-Path $BuildReleaseDir $alt
+        if (Test-Path -LiteralPath $altPath) {
+          $src = $altPath
+        }
       }
     }
     if (-not (Test-Path -LiteralPath $src)) {
       Write-Host "  [--] skip (not built): $name" -ForegroundColor Yellow
       continue
     }
-    $dest = Join-Path $TargetDir ([System.IO.Path]::GetFileName($src))
+    $dest = Join-Path $TargetDir $destName
     Copy-Item -LiteralPath $src -Destination $dest -Force
-    Write-Ok "copied $([System.IO.Path]::GetFileName($src))"
+    if ([System.IO.Path]::GetFileName($src) -ne $destName) {
+      Write-Ok "copied $([System.IO.Path]::GetFileName($src)) -> $destName"
+    } else {
+      Write-Ok "copied $destName"
+    }
     $copied += 1
   }