feat(account): unlink game accounts on the shard before an account is deleted (MODULE_API 1.20.0)

ACCOUNT_DELETION.md §4.4 (AD10, AD11). api.onUserDeleting queues every linked
account in the new shard_pending_unlinks table, then calls the sidecar's
DELETE /link/{account} (actor web:account-deletion) and drops the mirror on 200/404.
A shard that is away leaves the row pending, retried on WS reconnect and on a live
server.hello; a protected account (403) is refused and listed on Admin -> Shard as
still linked on the shard. A live mob.login without the deleted user's webId clears
the row. coreApi ^1.20.0; core-ref pinned to website#232's merge (7bd93b8).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

server/utils/uoLinkSocket.js

@@ -18,6 +18,7 @@ const uoLinkClient = require('./uoLinkClient')
 const shardIngest = require('./shardIngest')
 const shardState = require('../model/shardState/shardState.model')
 const newsGump = require('./newsGump')
+const accountDeletion = require('./accountDeletion')
 const log = require('../core').logger('uo-link-socket')
 
 const BACKOFF_MIN_MS = 1000
@@ -232,6 +233,10 @@ async function handleOpen() {
   backoff = BACKOFF_MIN_MS
   await uoLinkConfig.recordStatus({ status: 'connected', statusDetail: null, pluginConnected: true }).catch(() => {})
   await backfill()
+  // Unlinks an account deletion left queued while the bridge was away
+  // (ACCOUNT_DELETION.md §4.4). This is also the boot path: onBoot starts this
+  // socket, and boot itself never calls the shard. Not awaited; never rejects.
+  accountDeletion.retryPending()
 }
 
 // A ws.hello frame: mark it seen and, on a protocol mismatch, record the error