fix(downloads): treat missing site/adapter as permanent source failure

torrentSource threw plain Error for a missing site or a site without an
adapter definition, so submitDownload retried to max attempts, left the
plan and slot reserved, and sweepReservedPlans re-enqueued it forever
(agent runs stayed waiting on goal-settled). Throw SiteError
(not_found / unsupported) so the plan fails and the slot is released.
Needs image rebuild to take effect.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/src/modules/acquisition-organize/ports.ts

@@ -10,6 +10,7 @@ import {
   getSiteDefinition,
   type ProbeResult,
   type SecretResolver,
+  SiteError,
   type TorrentSource,
   type VerifyMethod,
 } from "@umt/adapters";
@@ -107,11 +108,12 @@ export function createPorts(
       return client;
     },
     async torrentSource({ release, site }) {
-      if (!site) throw new Error("站点不存在，无法获取种子");
+      // 永久性条件用 SiteError:submitDownload 据此把计划判失败并释放 Slot,而不是反复重试、Slot 一直 reserved
+      if (!site) throw new SiteError("", "not_found", "站点不存在，无法获取种子");
       const raw = (release.raw ?? {}) as Record<string, unknown>;
       const siteMeta = (raw._site ?? {}) as Record<string, unknown>;
       const defId = [str(siteMeta.adapterSiteId), site.key].find((k) => k && getSiteDefinition(k));
-      if (!defId) throw new Error(`站点 ${site.key} 没有可用的适配器定义`);
+      if (!defId) throw new SiteError(site.id, "unsupported", `站点 ${site.key} 没有可用的适配器定义`);
       const accounts = await ctx.db
         .selectFrom("site_account")
         .select(["auth_kind", "secret_ref"])