feat: role-aware presence bar, WebSocket logging fixes

- findAdminByKey returns role from admins.json (defaults to 'admin')
- JWT includes config-defined role instead of hardcoded 'admin'
- PresenceBar split into "who's here?" (page admins) and "connected"
  (bot/utility services with icon+color badges)
- Bot/utility roles appear in presence on all pages when connected
- usePresence hook uses refs to avoid WS reconnect on navigation
- WS auth log prints admin name instead of generic 'admin'
- WS connection log reads X-Forwarded-For for real client IP
- AuthContext stores adminRole from login response
- Uncomment admins.json Docker volume mount, add SELinux :z flags

Made-with: Cursor

backend/routes/auth.js

@@ -18,7 +18,7 @@ router.post('/login', (req, res) => {
   }
 
   const token = jwt.sign(
-    { role: 'admin', name: admin.name, timestamp: Date.now() },
+    { role: admin.role, name: admin.name, timestamp: Date.now() },
     JWT_SECRET,
     { expiresIn: '24h' }
   );
@@ -26,6 +26,7 @@ router.post('/login', (req, res) => {
   res.json({
     token,
     name: admin.name,
+    role: admin.role,
     message: 'Authentication successful',
     expiresIn: '24h'
   });