Old rar volumes: .s–.v only, not .x64/.x86

d4e53ca's .[s-z]NN took "Electric.Rain.Swift.3D.PS.v1.0.142.x64" for a
volume, so x86 and x64 builds would be one release.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/release/identity.ts

@@ -48,9 +48,9 @@ const SUFFIXES = [
 
 /** Strips per-file suffixes (volume numbers, archive and par2 extensions) from a filename. */
 export function fileStem(name: string): string {
-  // Old-style rar volumes after .r99 ("BD_NoTHing018.s41", "….s00"): only as the file's own extension, in lower case, so
-  // a season ("show.s01.rar", "Show.S01") stays.
-  let stem = name.trim().replace(/\.[s-z]\d{2}$/, '')
+  // Old-style rar volumes after .r99 ("BD_NoTHing018.s41", "….s00", ".t91", ".v81"): only as the file's own extension, in
+  // lower case, so a season ("show.s01.rar", "Show.S01") stays; not x or z (".x64", ".x86" builds; ".z01" goes with .zip).
+  let stem = name.trim().replace(/\.[s-v]\d{2}$/, '')
   let changed = true
   while (changed) {
     changed = false