Feature: Add APC UPS widget

[nicupavel]

Proposed change

This adds a widget for APC/Schneider UPS products using apcupsd. It shows UPS status, LOAD, Battery level, and running time left in case of power-failure.
It's a lighter alternative to monitor APC UPS than PeaNUT + NUT combo for systems with lower resources.

Closes #4426

Type of change

• New service widget
• Bug fix (non-breaking change which fixes an issue)
• New feature or enhancement (non-breaking change which adds functionality)
• Documentation only
• Other (please explain)

Checklist:

• If applicable, I have added corresponding documentation changes.
• If applicable, I have reviewed the feature / enhancement and / or service widget guidelines.
• I have checked that all code style checks pass using pre-commit hooks and linting checks.
• If applicable, I have tested my code for new features & regressions on both mobile & desktop devices, using the latest version of major browsers.

[shamoon]

Thanks. There are some obvious issues with the PR, doesn’t seem like anything major. And I have to ask, was this written partly or mostly by AI?

since I don’t have an APC UPS, please provide some example output from the device to test with.

[nicupavel]

And I have to ask, was this written partly or mostly by AI?

No.

since I don’t have an APC UPS, please provide some example output from the device to test with.

1. Download apcups_output.dmp (binary output from apcupsd)
2. Run: socat -U TCP4-LISTEN:3551,reuseaddr,fork OPEN:apcups_output.dmp
3. Test: socat -t 4 - tcp:127.0.0.1:3551
4. Edit services.yaml apcups widget with URL: TCP://127.0.0.1:3551

Should see this data on the widget:

[shamoon]

Thanks

[nicupavel]

Thank you!