Probe 7z listings and ZIP starts

7z keeps its file list at the end of the archive, so the 7z-tail
candidates (the last segment of the highest volume) were queued but
never probed, and the .7z.001 start only gave the type. The prober now
claims 7z-tail candidates after the archives; lib/sevenzip finds the end
header in the article, decodes the LZMA-packed header (a TypeScript port
of the LZMA SDK's reference decoder) and lists the files with their
sizes. An AES-encrypted header means passworded without names. Names
feed the inner name and the judge's fake rule.

An unsplit .7z of several segments now also gets a tail candidate, and
.zip files an archive candidate: their first segment's local headers
give the first entries and whether they are encrypted. Both in the Rust
edge and the TypeScript indexer.

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

lib/files/volumes.ts

@@ -1,10 +1,11 @@
 /**
  * Files whose first segment says what an archive holds: named first RAR
- * volumes (.part01.rar, .rar), 7z (.7z, .7z.001) and `.bin`, an extension
+ * volumes (.part01.rar, .rar), 7z (.7z, .7z.001: its type; the listing is at
+ * its end, the 7z-tail), ZIP (its first entries) and `.bin`, an extension
  * uploaders use for archive volumes too (sniffed by content).
  */
 export function isArchiveStart(name: string): boolean {
-  if (/\.bin$/i.test(name)) return true
+  if (/\.(bin|zip)$/i.test(name)) return true
   const volume = sevenZipVolume(name)
   if (volume === 0 || volume === 1) return true
   return /\.part0*1\.rar$/i.test(name) || (/\.rar$/i.test(name) && !/\.part\d+\.rar$/i.test(name))