Clarify Windows SDK refresh guidance

[Jake (JakeRadMSFT)]

Why

On Windows, Reload Window can retain the long-lived VS Code application environment after a successful SDK or runtime installation, leaving C# Doctor unable to detect the newly installed component. This is the public-doc companion to the vs-green product fix: it gives Windows users the full-process recovery path while preserving ordinary Reload Window guidance for macOS/Linux and non-install-related stale UI.

Related issues:

• [NETSDKE2E][v11]After installing SDK, "Reload Window" doesn't work normally in C# doctor. #3513
• [NETSDKE2E][v9.9]Creating project with Exception thrown 'System.ComponentModel.Win32Exception (2)'. #3479

Change

• Distinguish ordinary stale-view recovery from post-install environment refresh.
• Tell Windows users to exit all VS Code windows and relaunch from the Start menu or File Explorer, then restart Windows and recheck if detection still fails.
• Preserve the existing installation-safety and log-reporting guidance.

Validation

• git diff --check
• Confirmed the relative Windows troubleshooting link targets the existing Refresh a stale inherited PATH section.
• No targeted Markdown or link-check tooling is present in this repository.

Base and head

• Base: main at dd2c01a496218d937058e962aa4a71dbdf7440b2
• Head: jake-radzikowski-health-check-recovery-docs at 7799f7eee40473dac12a6de139bcb2b95e342381