Pending ladder by class, twins by content, dropped classes at the edge

The prober names 6% of the unnamed releases it finishes and the pending
queue (44M) grows eleven times faster than it probes. A sample of 44,530
finished pending rows shows the headers predict a name: size bucket, name
shape, completeness, tool and group separate 0% classes from 95% ones,
while the learner keyed on tool and group alone (LOG.md (130)).

- lib/release/classes.ts, names::pending_class, SQL pending_class():
  a release's class (size × shape × partial, 1..70), the three in step.
- Migration 6800: pending_releases.klass and target_bytes (the first
  target's article; candidates carry bytes now), pending_classes with
  each class's climbs, names, waiting and verdict, the claim's index.
- The ladder claims the classes with the best record first (a prior for
  the unexplored, at most a quarter of a claim from one), the cheapest
  target first within one, then the oldest of the rest; records classes
  like signatures and drops them at the same thresholds; discards their
  waiting releases. Claimed rows sorted in code: an UPDATE returns none.
- The rule set's droppedClasses: the edge keeps unnamed releases of a
  dropped class out of the pending store (counted as garbage), the
  explored sample excepted.
- hash_twins.ts: a probed file whose first 16 KiB and size match a named
  catalog release's names a pending release the probe didn't, and sets
  the inner name of a catalog release without one.
- pending:classes classes the rows from before and seeds the record from
  the finished ones; rules:classes publishes the dropped classes;
  releases:readable also marks the rows' candidates unreadable.

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

commands/releases_readable.ts

@@ -9,7 +9,8 @@ const CURSOR = 'readable'
 /**
  * The readable flag of the catalog's releases by today's classifier (isUnreadableName, LOG.md (129)): rows flagged
  * readable whose name no one can read ("Zx5AjNaK-mh7CFg6Hf8uu", "Description - Lt5nHjlo3RiuBb3C") get readable =
- * false, so the readable filter hides them (an inner name from the prober still shows them). By the release name,
+ * false, so the readable filter hides them (an inner name from the prober still shows them), and their probe
+ * candidates marked unreadable, the prober's first tiers. By the release name,
  * which is the shared file stem for most rows; not by the chunks' file names, which the edge judges from now on.
  * Batches by id, a dry run by default; --apply writes, and goes on from its cursor when run again.
  */
@@ -59,10 +60,16 @@ export default class ReleasesReadable extends BaseCommand {
       }
       changed += ids.length
       if (this.apply) {
-        if (ids.length > 0)
+        if (ids.length > 0) {
           await db.rawQuery(`UPDATE releases SET readable = false WHERE id = ANY(?::bigint[])`, [
             ids,
           ])
+          // Their probe candidates to the unreadable tiers, which the prober takes first (LOG.md (130)).
+          await db.rawQuery(
+            `UPDATE probe_candidates SET unreadable = true WHERE release_id = ANY(?::bigint[]) AND NOT unreadable`,
+            [ids]
+          )
+        }
         await db.rawQuery(
           `INSERT INTO worker_cursors (name, at, key) VALUES (?, now(), ?) ON CONFLICT (name) DO UPDATE SET at = excluded.at, key = excluded.key`,
           [CURSOR, String(to)]