## Describe your changes
When loadStateFile fails to unmarshal the state file, log whether the
file is empty (0 bytes) or has malformed content, including the byte
size.
## Issue ticket number and link
## Stack
<!-- branch-stack -->
### Checklist
- [ ] Is it a bug fix
- [ ] Is a typo/documentation fix
- [x] Is a feature enhancement
- [ ] It is a refactor
- [ ] Created tests that fail without the change (if possible)
- [ ] This change does **not** modify the public API, gRPC protocols,
functionality behavior, CLI / service flags, or introduce a new feature
— **OR** I have discussed it with the NetBird team beforehand (link the
issue / Slack thread in the description). See
[CONTRIBUTING.md](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTING.md#discuss-changes-with-the-netbird-team-first).
> By submitting this pull request, you confirm that you have read and
agree to the terms of the [Contributor License
Agreement](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT.md).
## Documentation
Select exactly one:
- [ ] I added/updated documentation for this change
- [x] Documentation is **not needed** for this change (explain why)
### Docs PR URL (required if "docs added" is checked)
aste the PR link from https://github.com/netbirdio/docs here:
https://github.com/netbirdio/docs/pull/__
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Improved state-file loading warnings by distinguishing empty files
from files containing malformed content.
* Preserved existing recovery behavior for corrupted state files.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
