feat(desktop): push publish tasks via AMQP topic dispatch WebSocket

Introduce a desktop.task.dispatch topic exchange with per-client routing
keys. Tenant-api publishes a task_available frame keyed by target client
ID when a publish job is created; every instance binds its own transient
queue and forwards to the matching WebSocket (/api/desktop/dispatch) it
owns. Desktop-client now prefers this push channel and only falls back
to HTTP /lease polling when the socket is down. Also drop admin-web
monitoring-plugin remnants and scope the publish modal account list to
publish platforms.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/components/PublishArticleModal.vue

@@ -11,7 +11,12 @@ import { articlesApi, mediaApi, publishJobsApi, resolveApiURL, tenantAccountsApi
 import { coverUploadRequired, deriveCoverFileName } from "@/lib/cover-requirements";
 import { formatDateTime } from "@/lib/display";
 import { formatError } from "@/lib/errors";
-import { getPublishPlatformMeta, normalizePublishPlatformId, normalizePublishPlatformIds } from "@/lib/publish-platforms";
+import {
+  getPublishPlatformMeta,
+  isPublishPlatformId,
+  normalizePublishPlatformId,
+  normalizePublishPlatformIds,
+} from "@/lib/publish-platforms";
 
 type PublishState = "immediate" | "queued" | "unavailable";
 
@@ -109,8 +114,19 @@ const platformMap = computed(() => {
   );
 });
 
+const publishAccounts = computed(() => {
+  return (accountsQuery.data.value ?? []).filter((account) => {
+    if (account.deleted_at) {
+      return false;
+    }
+
+    const platformId = normalizePublishPlatformId(account.platform);
+    return platformMap.value.has(platformId) || isPublishPlatformId(platformId);
+  });
+});
+
 const rawAccountMap = computed(() => {
-  return new Map((accountsQuery.data.value ?? []).map((account) => [account.id, account]));
+  return new Map(publishAccounts.value.map((account) => [account.id, account]));
 });
 
 const articlePlatformIds = computed(() => normalizePublishPlatformIds(detailQuery.data.value?.platforms ?? []));
@@ -118,8 +134,7 @@ const articlePlatformIds = computed(() => normalizePublishPlatformIds(detailQuer
 const accountCards = computed<PublishAccountCard[]>(() => {
   const preferredPlatforms = new Set(articlePlatformIds.value);
 
-  return [...(accountsQuery.data.value ?? [])]
-    .filter((account) => !account.deleted_at)
+  return [...publishAccounts.value]
     .map((account) => {
       const platformId = normalizePublishPlatformId(account.platform);
       const platform = platformMap.value.get(platformId);