Rebuild: first end-to-end runs; prefetch per chunk, executable rule, wire fixes

End to end on the workstation (coordinator:run, the API, edge:node, real
NNTP): a.b.e-book.french and a.b.cd.image.playstation2.dvdiso ranges.

- Prefetcher: every connection takes the next missing chunk (leased
  ranges first, in order); one connection per range (~26k lines/s) kept
  the worker waiting
- executable rule: releases of bare executables (malware floods named
  after films and software) are dropped; they were 92% of the catalog rows
  of the test ranges, 21% of the segments
- fragments per file (details once) and gzipped batch bodies; the JSON
  limit (1 MB by default) raised to 256 MB, empty strings kept (a rule
  count's key is '')
- release_chunks.batch_from is a bigint (boneless article numbers)
- tests get their own database; edge:bench --store times BatchStore:
  1.3 s for a boneless range (1.24 ms per release chunk)

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

tests/unit/edge/range_indexer.spec.ts

@@ -60,7 +60,7 @@ test.group('edge / RangeIndexer', () => {
     indexer.add([...post(5, 'Edge.File.2020.part1.rar', 3).slice(0, 2), ...post(500_000, 'Middle.File.2020.part1.rar', 3).slice(0, 2)], 600_000)
     indexer.finish()
     const batch = indexer.take()
-    assert.deepEqual(batch.fragments.map((f) => [f.name, f.number]), [['Edge.File.2020.part1.rar', 1], ['Edge.File.2020.part1.rar', 2]])
+    assert.deepEqual(batch.fragments.map((f) => [f.name, f.segments.map((s) => [s[0], s[3]])]), [['Edge.File.2020.part1.rar', [[1, 5], [2, 6]]]])
     assert.deepEqual(batch.counts.map((c) => [c.rule, c.articles]), [['incomplete', 2]])
     assert.lengthOf(batch.releases, 0)
   })