Add basic client scope to Keycloak realm config

Adds missing 'basic' client scope to the fastmcp realm configuration
to resolve Keycloak warning: "Referenced client scope 'basic' doesn't
exist. Ignoring"

The scope is configured as an openid-connect protocol scope that is
included in tokens but not displayed on the consent screen.

Author: stephaneberle9

examples/auth/keycloak_auth/keycloak/realm-fastmcp.json

@@ -180,6 +180,15 @@
         "consent.screen.text": "${offlineAccessScopeConsentText}",
         "display.on.consent.screen": "true"
       }
+    },
+    {
+      "name": "basic",
+      "description": "Basic client scope",
+      "protocol": "openid-connect",
+      "attributes": {
+        "include.in.token.scope": "true",
+        "display.on.consent.screen": "false"
+      }
     }
   ]
 }