Set default guest permissions to allow bringing up to 10 guests.

Updated guest schema and database models to increase the default value for `max_additional_guests` from 0 to 10 and enable `can_bring_guests` by default. This ensures new guests can bring additional attendees without manual configuration.

frontend/src/client/schemas.gen.ts

@@ -1134,7 +1134,7 @@ export const GuestCreateSchema = {
         },
       ],
       title: "Max Additional Guests",
-      default: 0,
+      default: 10,
     },
     dietary_restrictions: {
       anyOf: [
@@ -1179,7 +1179,7 @@ export const GuestCreateSchema = {
         },
       ],
       title: "Can Bring Guests",
-      default: false,
+      default: true,
     },
     invitation_code: {
       anyOf: [
@@ -1259,7 +1259,7 @@ export const GuestReadSchema = {
         },
       ],
       title: "Max Additional Guests",
-      default: 0,
+      default: 10,
     },
     dietary_restrictions: {
       anyOf: [
@@ -1304,7 +1304,7 @@ export const GuestReadSchema = {
         },
       ],
       title: "Can Bring Guests",
-      default: false,
+      default: true,
     },
     id: {
       type: "string",