refactor: remove command field from GraphQL Alarm type

command is generated internally and has no informational value to API
consumers, so stop exposing it on getAlarms/getAlarm/setAlarm.

README.md

@@ -82,7 +82,6 @@ query {
   getAlarms {
     id
     cronExpression
-    command
     isEnabled
   }
 }
@@ -92,16 +91,16 @@ query {
 ```graphql
 mutation {
   setAlarm(
-    cronExpression: "45 6 * * 1-5", 
+    cronExpression: "45 6 * * 1-5",
     isEnabled: true
   ) {
     id
     cronExpression
-    command
+    isEnabled
   }
 }
 ```
-*(Note: The `command` is managed automatically by the API and cannot be overridden, to prevent command injection into the system crontab.)*
+*(Note: `command` is generated automatically by the API and is **not** accepted as an input parameter on `setAlarm`, to prevent command injection into the system crontab.)*
 
 **Delete an alarm:**
 ```graphql