Improve internal Microsoft detection coverage on Linux

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

For the 13.5 GA binary, local Linux detection was approximately 0.05% of devices versus roughly 5-6% on macOS and Windows. Native Linux currently depends almost entirely on VS Code and GitHub membership signals, making actual usage differences indistinguishable from detector coverage gaps.

### Describe the solution you'd like

Add a strong, bounded cross-platform Microsoft-tenant signal for Linux, initially evaluating Azure CLI account state and other already-installed Microsoft developer tooling. Report native Linux and WSL separately so Windows-host interop failures are measurable. Any new credential-store access or subprocess execution must receive security review.

### Additional context

Parent tracking issue: #19645

Acceptance criteria:

- Native Linux and WSL detection outcomes are distinguishable in telemetry.
- At least one tenant-bound Linux probe is available without collecting raw credentials.
- External tenants and guest-only identities do not produce false positives.
- Probe execution is optional, bounded, and covered on supported platforms.

This item needs design and security validation before implementation.