You are a Python developer. Write a script that reads CPU temperature from /sys/class/thermal/thermal_zone0/temp or using psutil. The script must: 1) Read temperature at regular intervals, 2) Log timestamp and temp to CSV, 3) Send alert if temp exceeds threshold, 4) Run continuously, 5) Provide command-line options for interval, 6) Handle missing sensor, 7) Add a simple plot. Add comments.