Fix CronJob model API compatibility and register BackHandler in SettingsScreen

app/src/main/java/com/m57/hermescontrol/data/model/CronJob.kt

@@ -3,8 +3,25 @@ package com.m57.hermescontrol.data.model
 data class CronJob(
     val id: String,
     val name: String,
-    val schedule: String?,
+    val schedule: Any?,
     val state: String?,
     val last_run_status: String?,
     val next_run: String?,
-)
+    val schedule_display: String? = null,
+    val last_status: String? = null,
+    val next_run_at: String? = null,
+) {
+    val scheduleText: String
+        get() =
+            when (schedule) {
+                is String -> schedule
+                is Map<*, *> -> (schedule["display"] as? String) ?: schedule_display ?: ""
+                else -> schedule_display ?: ""
+            }
+
+    val lastRunStatus: String
+        get() = last_run_status ?: last_status ?: ""
+
+    val nextRunTime: String
+        get() = next_run ?: next_run_at ?: ""
+}