The par2 merge: releases whose files one par2 set describes become one

The prober stores, per probed article that starts a file, the MD5 of its
first 16 KiB (file_hashes), and per par2 body the set's whole file list
(par2_files, par2_sets): FileDesc holds the same hash per file, whatever
the file was renamed to. releases:merge (the merger service, no NNTP)
merges every minute the releases of one group, posted within 48 hours of
a release holding the set's par2, whose files the set describes, into the
one with the most files: chunks, probe candidates, inspections, hashes and
counts move; the par2's shared name when none was readable; release_merges
keeps what went where. Obfuscated uploads whose files were each a release
of their own ("[9/20] - "14f5999a…"", hep: 13,232) become one.

Also: corpus_sweep.py counts the marked ranges without psql's command tag.

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

REBUILD.md

@@ -228,6 +228,17 @@ reads the probe queue's first articles (`lone`, `par2`, `archive`) and
 stores per release whether it's passworded and its inner name, which search,
 the web interface and Newznab use.
 
+Built: the par2 merge (2026-10-12; `releases:merge`, the `merger` service,
+LOG.md 2026-10-12 (13)). The prober stores per probed file start the MD5 of
+its first 16 KiB (`file_hashes`) and per par2 body its set's file list
+(`par2_files`, `par2_sets`), which holds the same hash per file whatever the
+file was renamed to. Every minute the merger merges the releases of one
+group, posted within 48 hours of a release holding the set's par2, whose
+files the set describes, into the one with the most files (chunks,
+candidates, inspections, counts; the par2's shared name when none was
+readable); `release_merges` keeps what went where. Obfuscated uploads whose
+files were each a release of their own (`lone` candidates) become one.
+
 **Backlog: voyager 1's features not in voyager 2** (CONCEPT.md decisions;
 voyager 1's data exported to `/mnt/bulk/usenet-rebuild/v1-export/` on
 homelab: `voyager1-tables.dump` with 2.76 M spots, upload signatures,