<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#35724
- Fixes issues 1 and 2 of the referenced bug ticket
- Also fixes [this
issue](https://github.com/fleetdm/fleet/pull/35739/files#r2548349172)
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
For unreleased bug fixes in a release candidate, one of:
- [x] Alerted the release DRI if additional load testing is needed
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added upgrade code support to Windows maintained applications for
improved MSI installer tracking and management.
* **Documentation**
* Updated Windows onboarding instructions with more precise manifest
path guidance and concrete command examples for the maintained-apps
generator.
* **Tests**
* Added comprehensive test coverage for upgrade code association with
maintained applications.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
jacobshandling
3ca1ff4754