Fix marketplace path matching for Windows junctions

[copyberry]

Fix marketplace path matching for Windows junctions

Why

Equivalent local source paths can fail to match an already-added marketplace, and redirected managed roots can lose their managed classification on Windows.

What changed

• Compare local marketplace sources after filesystem normalization.
• Reuse the resolved request path when locating an existing local marketplace so retargeting a configured junction does not switch the returned root.
• Accept both the configured managed root and its canonical target on Windows while continuing to reject unowned aliases to that target.

Testing

Add Windows regression tests for canonical and legacy path spellings, retargeted local-source junctions, and redirected managed roots with unowned aliases.

[github-actions]

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