The pending ladder in the prober: unnamed releases probed cheapest first, signatures learned, the named moved into the catalog

pending_ladder.ts claims the oldest waiting pending releases' next target
(par2, archive, lone, 7z-tail in that order) as at least PENDING_SHARE of each
claim; a usable name (the largest named file of a par2 set or a listing, or a
lone file's yEnc name, neither packaging nor random) hands the release to the
namer, no name the next target or the end of the climb; climbs count on
pending_signatures per (tool, group, poster) and (tool, group), and a signature
with 100 climbs and 0.5% named or fewer is dropped: its waiting releases are
discarded without a probe, the rules' sample excepted. pending_namer.ts reads
a named release's articles again from the corpus or by XOVER and writes it to
the catalog under the pending key (source weak-stem, the name as inner name)
with its chunk and candidates. Migration 6400; config PENDING_*.

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

app/services/corpus.ts

@@ -42,13 +42,13 @@ class Corpus {
     return coordinatorConfig.corpus.dir
   }
 
-  private rangeDir(range: CorpusRange) {
-    return join(this.dir!, range.group, `${range.start}-${range.end}`)
+  private rangeDir(range: CorpusRange, dir = this.dir!) {
+    return join(dir, range.group, `${range.start}-${range.end}`)
   }
 
-  private path(range: CorpusRange, span: ChunkSpan) {
+  private path(range: CorpusRange, span: ChunkSpan, dir = this.dir!) {
     const index = Math.floor((span.from - range.start) / coordinatorConfig.chunkArticles)
-    return join(this.rangeDir(range), `${String(index).padStart(4, '0')}-${span.from}-${span.to}.gz`)
+    return join(this.rangeDir(range, dir), `${String(index).padStart(4, '0')}-${span.from}-${span.to}.gz`)
   }
 
   /** Whether every chunk of the range is stored (its range.json). */
@@ -69,10 +69,10 @@ class Corpus {
     )
   }
 
-  /** A stored chunk, or null. */
-  async read(range: CorpusRange, span: ChunkSpan): Promise<Buffer | null> {
-    if (!this.dir) return null
-    return readFile(this.path(range, span)).catch(() => null)
+  /** A stored chunk, or null (`dir`: another corpus than CORPUS_DIR's, the namer's tests). */
+  async read(range: CorpusRange, span: ChunkSpan, dir = this.dir): Promise<Buffer | null> {
+    if (!dir) return null
+    return readFile(this.path(range, span, dir)).catch(() => null)
   }
 
   /**