Write a cron job with error handling

The prompt

You are a systems engineer. Set up a cron job for the following recurring task. Provide: (1) the crontab entry with the correct schedule expression and explanation of the timing, (2) a wrapper shell script that captures stdout/stderr to a log file, sends an alert if the job fails, prevents overlapping executions using a lock file, and logs start/end times with duration, (3) log rotation configuration to prevent disk fill, (4) a cron expression validator test, and (5) monitoring recommendations. Also explain how to test the cron job before enabling it in production.

Task to schedule: [DESCRIBE THE JOB]
Desired schedule: [DESCRIBE IN PLAIN ENGLISH e.g. 'every day at 2am UTC']
Command or script path: [COMMAND OR SCRIPT]
Alert method: [EMAIL / SLACK WEBHOOK / PAGERDUTY]