Add duty cycle protection parameters to thermostat climate platform

[janboshoff75]

Component name

thermostat

Link to component documentation on our website

https://esphome.io/components/climate/thermostat.html

Describe the enhancement

Summary

Add max_cooling_run_time/max_heating_run_time and forced_rest_period configuration options to the thermostat climate platform to automatically enforce duty cycle limits and prevent equipment damage from excessive continuous operation.

The problem

Many refrigeration systems, heat pumps, and other HVAC equipment can be damaged by running continuously for extended periods without rest. Currently, ESPHome's thermostat platform only provides minimum timing controls (min_cooling_run_time, min_cooling_off_time, etc.) but no maximum runtime protection. There is max_cooling_run_time, but this is more related to triggering supplemental cooling.

Users must implement custom logic with globals, intervals, and lambda functions to achieve duty cycle protection, which is error-prone and requires significant boilerplate code.

Proposed solution

climate:
  - platform: thermostat
    # ... existing config ...
    max_cooling_run_time: 5h        # Maximum continuous cooling time
    max_heating_run_time: 3h        # Maximum continuous heating time  
    forced_rest_period: 45min       # Mandatory off time after max runtime

Behavior

• When max_cooling_run_time is exceeded, automatically switch to CLIMATE_MODE_OFF
• Prevent any heating/cooling actions for the duration of forced_rest_period
• Automatically resume previous mode after rest period expires
• Log warnings when duty cycle protection activates
• Reset runtime counter when equipment naturally cycles off before reaching maximum

Use cases

• RV/marine refrigeration systems without sophisticated controllers
• DIY heat pump controllers
• Industrial process cooling
• Greenhouse climate control
• Fermentation temperature control

Similar functionality exists in: Many commercial HVAC controllers, industrial PLCs, and dedicated refrigeration controllers.
Estimated implementation complexity: Medium - would extend existing thermostat state machine and timing logic.

Anything else?

This feature would benefit:

• Refrigerators/freezers - Prevent compressor damage from continuous operation
• Heat pumps - Avoid overheating and efficiency loss
• Water pumps - Prevent motor burnout
• Industrial equipment - Mandatory duty cycles for safety/longevity

Real-world example: Refrigeration compressors typically need a rest period after 4-6 hours of continuous operation to prevent overheating and ensure proper oil circulation.

[github-actions[bot]]

🏷️ I've automatically added the component: thermostat label to help categorize this feature request.