Rebuild: settling quiet releases

Hourly in coordinator:run: a release unchanged for 6 hours is settled,
complete when every file its [i/N] counter announced was found, unknown
without a counter (phase 2 reads par2 sets for those). Partial index on
unsettled releases.

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

app/services/settler.ts

@@ -0,0 +1,28 @@
+import db from '@adonisjs/lucid/services/db'
+
+/** Releases unchanged for this long are settled (ranges are read in order; the merger adds within minutes). */
+const QUIET_HOURS = 6
+const BATCH = 50_000
+
+/**
+ * Settles releases (REBUILD.md, part 8): once nothing has been added for
+ * QUIET_HOURS, its completeness is decided: complete when every file the
+ * [i/N] counter announced was found, unknown without a counter (phase 2
+ * reads par2 sets for those). Phase 2 picks its work from settled releases.
+ */
+class Settler {
+  async run(): Promise<number> {
+    let settled = 0
+    while (true) {
+      const { rowCount } = await db.rawQuery(
+        `UPDATE releases SET settled_at = now(), complete = CASE WHEN file_total IS NULL THEN NULL ELSE files >= file_total END
+         WHERE id IN (SELECT id FROM releases WHERE settled_at IS NULL AND last_seen_at < now() - make_interval(hours => ?) LIMIT ?)`,
+        [QUIET_HOURS, BATCH]
+      )
+      settled += rowCount ?? 0
+      if ((rowCount ?? 0) < BATCH) return settled
+    }
+  }
+}
+
+export default new Settler()