Settle every 5 min in rounds of 200k, not ~3M at once hourly; range blocks in a loop of their own

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

app/services/settler.ts

@@ -18,9 +18,10 @@ const BATCH = 50_000
  * reads par2 sets for those). Phase 2 picks its work from settled releases.
  */
 class Settler {
-  async run(): Promise<number> {
+  /** Up to `batches` batches of BATCH (all there are without). */
+  async run(batches = Infinity): Promise<number> {
     let settled = 0
-    while (true) {
+    for (let batch = 0; batch < batches; batch++) {
       // Their probe candidates become claimable (Prober.claim), the unreadable ones first.
       const { rows } = await db.rawQuery(
         `WITH settled AS (
@@ -39,6 +40,7 @@ class Settler {
       settled += n
       if (n < BATCH) return settled
     }
+    return settled
   }
 }