core/config: LoadModelConfigsFromPath treats .yaml.bak files as active model configs

[leinasi2014]

LocalAI version:

• current master (reproduced on a distributed deployment and patched in fork commit e0dc41d)

Environment, CPU architecture, OS, and Version:

• Reproduced against a LocalAI distributed deployment using model configs loaded from /models
• Also reproduced directly from source in core/config/ModelConfigLoader

Describe the bug
LoadModelConfigsFromPath() currently matches files using strings.Contains(file.Name(), ".yaml") / strings.Contains(file.Name(), ".yml").
Because of that, backup files like model.yaml.bak or model.yaml.bak.20260420 are also loaded as active model configs.

In practice this means stale backup configs can override the live config with the same name: and make /api/models/config-json/... and runtime behavior drift away from the actual model.yaml file.

To Reproduce

1. Put these files in the models directory:
   • foo.yaml
   • foo.yaml.bak
   • foo.yaml.bak.123
2. Give foo.yaml and foo.yaml.bak the same name: but different description: or parser/template settings.
3. Start LocalAI and load configs from that directory.
4. Observe that the backup file is treated as a real config and can override the active one.

Minimal example:

• foo.yaml => name: foo-model, description: formal config
• foo.yaml.bak => name: foo-model, description: backup config

Expected behavior
Only files whose real extension is exactly .yaml or .yml should be loaded as configs. Backup files such as .yaml.bak or .yaml.bak.<timestamp> should be ignored.

Logs
No special runtime log is required to reproduce. The behavior is visible through loaded config state and API responses.

Additional context
I verified this in a live deployment by quarantining *.yaml.bak* files out of /models and restarting LocalAI. After that, /api/models/config-json/... and /api/models/edit/... immediately started returning the actual live config.

I also prepared a minimal fix and regression test in my fork:

• commit: e0dc41d059b618afe7f6bc481dc88fa65b3f3be0
• branch: codex/fix-model-config-loader-yaml-suffix
• fork branch URL: https://github.com/leinasi2014/LocalAI/tree/codex/fix-model-config-loader-yaml-suffix

The fix changes the loader to check filepath.Ext(file.Name()) instead of substring matching, and the regression test verifies that:

• foo.yaml is loaded
• foo.yaml.bak is ignored
• foo.yaml.bak.123 is ignored
• backup files do not override the active config