Seed leases respect the backfill's disk limits

No new range while the database's NVMe part or the hdd tablespace is over
BACKFILL_MAX_NVME_GB / BACKFILL_MAX_HDD_GB; nodes ask again a minute later.
seed:status says when leasing is paused. The NVMe part was at 47 GB of 50
with a plan for all of a.b.ath queued.

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

app/services/BackfillService.ts

@@ -90,7 +90,15 @@ class BackfillService {
   }
 
   /** True when both parts of the database are under their limits, else why not. */
-  private async room(maxDefaultGb: number, maxHddGb: number): Promise<true | string> {
+  /**
+   * Whether the database has room for more history: the default tablespace
+   * (NVMe) and tablespace `hdd` against BACKFILL_MAX_NVME_GB/_HDD_GB. Seed
+   * leases (CONCEPT.md D38) check the same limits.
+   */
+  async room(
+    maxDefaultGb = indexerConfig.backfill.maxDefaultGb,
+    maxHddGb = indexerConfig.backfill.maxHddGb
+  ): Promise<true | string> {
     const { rows } = await db.rawQuery(
       `SELECT spcname, pg_tablespace_size(oid) AS bytes FROM pg_tablespace WHERE spcname IN ('pg_default', 'hdd')`
     )