ref(core): Add MonitorConfigUtils to convert schedules to monitor configs (#6217)

* ref(core): Add MonitorConfigUtils to convert schedules to monitor configs

Framework-free conversion of a 6 field cron expression, fixed rate or
fixed delay into a MonitorConfig, plus period parsing, so the Spring and
Quartz integrations can share it.

* fix(core): Only send monitor configs Sentry reads the same way

Return no config when day of month and day of week are both set, for
cron syntax Sentry rejects, and for zones that are not IANA region IDs.
Whole-hour fixed offsets map to Etc/GMT zones. Intervals use hours or
days when they divide evenly.

* ref(core): Add MonitorConfigUtils.fromSpringScheduled

Move the Spring day-of-week rewrite and the JVM default zone rule into
core so the three Spring modules share them.

* fix(core): Return no config for stepped single value ranges

Spring and Quartz run 10-10/2 only at 10, cronsim steps to the field max.

* fix(core): Read Spring crons per parser and skip fixed delays

Spring before 5.3 steps day of month */n from 0 and can run at midnight
when both day fields are set; read its crons that way. Spring 5.3 runs
#5 in months without a fifth weekday, so return null for it. A fixed
delay drifts from any interval, so it gets no config.

* fix(core): Keep Sunday-only day of week ranges

SUN-SUN was rewritten to 0-7, which crontab reads as every day.

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(core): Use a 2 minute check-in margin for crons with fixed seconds

Dropping a non-zero seconds field makes check-ins arrive up to 59s after
the expected minute, which a 1 minute margin barely covers.

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: wedamija

sentry/api/sentry.api

@@ -8148,6 +8148,12 @@ public final class io/sentry/util/MapObjectWriter : io/sentry/ObjectWriter {
 	public fun value (Z)Lio/sentry/util/MapObjectWriter;
 }
 
+public final class io/sentry/util/MonitorConfigUtils {
+	public static fun fromSchedule (Ljava/lang/String;Ljava/lang/String;Ljava/lang/Long;)Lio/sentry/MonitorConfig;
+	public static fun fromSpringScheduled (Ljava/lang/String;Ljava/lang/String;Ljava/lang/Long;Ljava/lang/Long;Z)Lio/sentry/MonitorConfig;
+	public static fun parsePeriodMillis (Ljava/lang/String;Ljava/util/concurrent/TimeUnit;)Ljava/lang/Long;
+}
+
 public final class io/sentry/util/Objects {
 	public static fun equals (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public static fun hash ([Ljava/lang/Object;)I