Add admin shard control: config, status, town crier (phase 5)

- admin/uoLink.controller.js: GET /admin/uo-link/config (masked config + live
  health + ingestion stats from the socket/broadcaster); PUT to save base/ws
  URL + write-only token + protocol + enabled, which (re)starts or stops the WS
  ingest client and activity-logs the change; POST/DELETE /uo-link/towncrier to
  publish/remove town-crier messages; GET /uo-link/stream (admin SSE channel,
  full feed incl. audit/cheat). Mounted adminOnly with express-validator guards
  + #swagger annotations (new "Admin · Shard" tag, TownCrierRequest schema).
- server.js: startup probe (checkUoLink) that logs reachability and warns
  loudly on a protocol mismatch when the integration is enabled.
- client: api.admin uo-link methods; ShardAdmin.jsx control panel (status
  panel with ingestion stats, config form, town crier) modeled on
  DiscordBotAdmin; wired into AdminLayout nav/titles + the /admin/shard route.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011qPmpmVH1xGCiZoz9m9vW3

client/src/routes/admin/AdminLayout.jsx

@@ -37,6 +37,7 @@ const IconKey = () => <Icon><circle cx="8" cy="12" r="4" /><path d="M12 12h9M18
 const IconBot = () => <Icon><rect x="4" y="8" width="16" height="11" rx="2" /><path d="M12 8V4M8 13h.01M16 13h.01M9 17h6" /></Icon>
 const IconPulse = () => <Icon><path d="M3 12h3l2 6 4-14 2 8h7" /></Icon>
 const IconUser = () => <Icon><circle cx="12" cy="8" r="4" /><path d="M4 21a8 8 0 0 1 16 0" /></Icon>
+const IconShard = () => <Icon><path d="M12 2l7 6-7 14-7-14z" /><path d="M5 8h14" /></Icon>
 
 // Nav is grouped into collapsible categories. A group with no `title` renders
 // its items ungrouped (Dashboard at top, Account at bottom). Each item's `roles`
@@ -72,6 +73,7 @@ const NAV = [
       { to: '/admin/hero', label: 'Hero Editor', icon: IconHero, roles: ['admin'] },
       { to: '/admin/auth-providers', label: 'Authentication', icon: IconKey, roles: ['admin'] },
       { to: '/admin/discord-bot', label: 'Discord Bot', icon: IconBot, roles: ['admin'] },
+      { to: '/admin/shard', label: 'Shard (uo-link)', icon: IconShard, roles: ['admin'] },
       { to: '/admin/bot-activity', label: 'Web Bot Activity', icon: IconPulse, roles: ['admin'] },
     ],
   },
@@ -95,6 +97,7 @@ const TITLES = {
   '/admin/activity': 'Activity Log',
   '/admin/bot-activity': 'Web Bot Activity',
   '/admin/discord-bot': 'Discord Bot',
+  '/admin/shard': 'Shard (uo-link)',
   '/admin/auth-providers': 'Authentication',
   '/admin/users': 'Users',
   '/admin/account': 'Account Security',