Run multi-instance, Terminal Services, architecture, and slow-machine validation

## Objective

Exploratorily test concurrent launches, rapid activation races, multiple Windows users, Terminal Services/Remote Desktop, different install paths, x64, non-Apple Windows on ARM, and a slow device such as Surface Go 2. Klaus owns both suitable ARM and Surface Go 2 hardware and can be asked to test.

## Completion guidance

- Keep the implementation focused on the objective while allowing the assignee to improve the approach based on research.
- Document important decisions, rejected alternatives, dependencies, and follow-up work.
- Add or update tests and documentation appropriate to the work.
- Verify locally and in CI where the task changes code or generated artifacts.

No source files, tests, or entry points are named. Start by turning the listed launch, user, architecture, install-path, and slow-device scenarios into a validation matrix, using Klaus's ARM and Surface Go 2 hardware where available; done means the scenarios and important decisions, dependencies, rejected alternatives, follow-up work, and resulting tests or documentation are recorded.

Written by the indexing model from the issue text.