par2 file lists dropped once their holders are final; late candidates claimable

Most par2 sets describe readable uploads whose files are never hashed, so they
were never complete and kept forever (19 GB). Candidates added to a release
after it settled were never marked ready (93,642 since 2026-10-13); the batch
store and merge mark them now, migration 5100 repairs the waiting ones
(LOG.md 2026-10-20 (87)).

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

app/services/par2_merger.ts

@@ -115,7 +115,7 @@ export class Par2Merger {
         if (!this.stopped && Date.now() - prunedAt >= PRUNE_EVERY_MS) {
           prunedAt = Date.now()
           const pruned = await new Par2Pruner().round(PRUNE_BUDGET_MS)
-          if (pruned.rows) logger.info(`Pruned ${pruned.rows} par2 file rows: ${pruned.complete} complete sets, ${pruned.judged} judged.`)
+          if (pruned.rows) logger.info(`Pruned ${pruned.rows} par2 file rows: ${pruned.complete} complete sets, ${pruned.judged} judged, ${pruned.final} final.`)
         }
         const round = await this.round()
         if (round.merges > 0) logger.info(`Merged ${round.releases} releases into ${round.merges} by par2 set (${round.sets} sets checked).`)
@@ -335,6 +335,12 @@ export class Par2Merger {
       for (const table of ['release_chunks', 'probe_candidates', 'release_inspections', 'file_hashes']) {
         await trx.rawQuery(`UPDATE ${table} SET release_id = ? WHERE release_id = ANY(?)`, [target.id, others])
       }
+      // An unsettled member's candidates into a settled target: the settler won't come by again to make them claimable.
+      await trx.rawQuery(
+        `UPDATE probe_candidates pc SET ready = true, unreadable = NOT r.readable FROM releases r
+         WHERE r.id = ? AND r.settled_at IS NOT NULL AND pc.release_id = r.id AND pc.status = 'waiting' AND NOT pc.ready`,
+        [target.id]
+      )
       // A set held by the target already, or by two of the others (a par2 and its repost), isn't held twice (every
       // round failed on the primary key from 20:28 UTC on 2026-10-12; LOG.md 2026-10-12 (30)).
       await trx.rawQuery(