Seed leases alternate between priorities; article relay can be off

Half the live leases go to higher-priority ranges, the rest to the others,
so a slow recent gap runs beside older history. With no article
connections the article relay answers 503 instead of waiting forever.

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

app/services/RemoteContentService.ts

@@ -2,6 +2,7 @@ import { randomUUID } from 'node:crypto'
 import { Job, Worker } from 'bullmq'
 import logger from '@adonisjs/core/services/logger'
 import queueConfig from '#config/queue'
+import nntpConfig from '#config/nntp'
 import QueueService from '#services/QueueService'
 import NntpService from '#services/NntpService'
 import ContentService, { describeContent } from '#services/ContentService'
@@ -24,6 +25,7 @@ export interface RemoteJob {
 }
 
 export class JobLost extends Error {}
+export class ArticleRelayOff extends Error {}
 
 /**
  * Content inspection and archive walks on seeding nodes (CONCEPT.md D41).
@@ -99,6 +101,8 @@ class RemoteContentService {
 
   /** One article body for a relay node, on this process's NNTP pool. Null when the server doesn't have it. */
   async article(messageId: string): Promise<Buffer | null> {
+    // NNTP_POOL_SIZE 0 (SEED_ARTICLE_CONNECTIONS=0): no connections for this; acquire() would wait forever.
+    if (nntpConfig.poolSize <= 0) throw new ArticleRelayOff('Article relay is off (SEED_ARTICLE_CONNECTIONS=0)')
     const conn = await NntpService.acquire()
     let failed = false
     try {