Single-archive rules: stub archives and nonsense pieces dropped at the edge

The judge gets each file's articles seen and bytes, and whether the window
closed on the release. A settled release of one unsplit archive posted to 2+
groups is dropped as a stub archive when its articles are <= 256 KiB with the
release >= 1 MB, or it is in 4+ groups, or by a webmail poster (those two
under 100 MB); releases touching music, e-book, comics, tabs or fonts groups
are exempt. A one-article archive of 100 kB-1 MB under a release-like,
unscrambled name without spaces or an e-book format is dropped as a nonsense
piece. Both switched by the rule set (dropStubArchives, dropNonsensePieces),
mirrored in lib/rules, sampled like every drop (LOG.md (123)-(127)).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

lib/rules/index.ts

@@ -1,2 +1,2 @@
 export { uploadTool, signatureGroup, signatureKey, explored } from './upload_tools.js'
-export { RuleSet, DEFAULT_RULES, isRandomFile, isScrambledFile, ownerOf, posterWords, type Rules, type Verdict } from './rule_set.js'
+export { RuleSet, DEFAULT_RULES, isRandomFile, isScrambledFile, ownerOf, posterWords, stubArchiveLegs, isNonsensePiece, STUB_ARTICLE_BYTES, STUB_MIN_BYTES, STUB_MAX_BYTES, STUB_WIDE_GROUPS, NONSENSE_MIN_BYTES, NONSENSE_MAX_BYTES, type Rules, type Verdict, type JudgedFile } from './rule_set.js'