fix: admin panel route returning JSON instead of rendering HTML

ISSUE:
Admin panel at /admin returned JSON instead of EJS template
User authenticated successfully but saw raw data

FIX:
Changed res.json() to res.render('admin/dashboard')
Added user, mappings, csrfToken to template context

FILES MODIFIED:
- services/arbiter-3.0/src/routes/admin.js (5 lines changed)

TESTING:
Visit /admin after Discord OAuth, should show HTML UI

Signed-off-by: Claude (Chronicler #57) <claude@firefrostgaming.com>

services/arbiter-3.0/src/routes/admin.js

@@ -13,7 +13,11 @@ const isAdmin = (req, res, next) => {
 // TODO: Replace with full beautiful UI from live bot.js
 router.get('/', isAdmin, (req, res) => {
   const mappings = getRoleMappings();
-  res.json({ message: "Admin Panel UI", mappings }); 
+  res.render('admin/dashboard', { 
+    user: req.user, 
+    mappings,
+    csrfToken: req.csrfToken()
+  });
 });
 
 router.post('/mappings', isAdmin, express.json(), (req, res) => {