Rebuild: phase 1 modules from the current app, ordered by pipeline stage

lib/nntp (XOVER client, Xref, GROUP), lib/headers (subjects, file keys,
segments from overview lines; the yEnc path stays behind for phase 2),
lib/release (identity, random names, now in lib), lib/files (aggregator,
volume names), lib/rules (posting tools, owner by priority, release
verdicts), lib/chunks (release chunk codec). Their unit tests came along;
new ones for codec, rules and volumes.

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

lib/rules/index.ts

@@ -0,0 +1,2 @@
+export { uploadTool, signatureGroup, signatureKey, explored } from './upload_tools.js'
+export { RuleSet, DEFAULT_RULES, isRandomFile, ownerOf, type Rules, type Verdict } from './rule_set.js'