fix: restore modular admin structure - all modules now working

ISSUE:
We accidentally built a flat admin.js that replaced the working modular system
All modules (Players, Servers, Grace, Audit, Roles, Financials) exist in /routes/admin/

FIX:
1. Backed up flat admin.js to admin-backup-chronicler57.js
2. Changed index.js to require('./routes/admin/index')
3. Restored proper modular structure

MODULES RESTORED:
- /admin/players - Full CRUD with detail view, tier changes, staff toggle
- /admin/servers - Server matrix with Pterodactyl integration
- /admin/grace - Grace period management
- /admin/audit - Audit log feed
- /admin/roles - Role diagnostics
- /admin/financials - Revenue analytics

ALL ORIGINAL FUNCTIONALITY RESTORED

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

services/arbiter-3.0/src/index.js

@@ -9,7 +9,7 @@ const csrf = require('csurf');
 const cors = require('cors');
 
 const authRoutes = require('./routes/auth');
-const adminRoutes = require('./routes/admin');
+const adminRoutes = require('./routes/admin/index');
 const webhookRoutes = require('./routes/webhook');
 const stripeRoutes = require('./routes/stripe');
 const { registerEvents } = require('./discord/events');