feat(shard): admin write plane, help-page queue, and public champion board

Wire up the three uo-link sidecar surfaces that weren't integrated yet.

Champion spawns
- Ingest champ.update/champ.remove into a new shard_champs table (served from
  our own store, like online/houses); public /site/champs board with a nav link,
  live via the existing SSE feed (champ.* added to the public allowlist).

Staff write plane (admin + moderator)
- kick / ban / unban / broadcast via /admin/shard/*; actor is stamped server-side
  from the session, never the browser. Sidecar status codes mapped (403 disabled/
  protected, 404 unknown, 503/504 transient). admin.audit events are logged and
  surfaced at /admin/shard/audit.
- New admin "In-Game Ops" view (/admin/shard-ops), plus per-account Kick/Ban/Unban
  on the user-detail and character views (ShardAccountActions, self-gated to staff).

Help-page (support) queue
- Ingest page.new/updated/closed into a new shard_pages table; respond/close via
  /admin/shard/pages/*. Champ board and page queue are snapshotted from the
  sidecar's /champs and /pages on every WS (re)connect (guarded so a failed call
  never wipes local state).

Verified live end-to-end against MariaDB + the Rust sidecar + ServUO; unit tests
cover ingest routing (shardIngest.champsPages.test.js). Swagger regenerated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0114TpmrNW4wNXsHq5CR72jQ

server/src/utils/shardBroadcast.js

@@ -33,6 +33,9 @@ const PUBLIC_KINDS = new Set([
   'server.hello',
   'server.shutdown',
   'server.crashed',
+  // Champion-spawn board deltas — the public Champions page renders these live.
+  'champ.update',
+  'champ.remove',
 ])
 
 // Open response streams per channel.