T-6: Move serverList and cloudNavigation sheets into WindowFeature

[kirich1409]

Part of EPIC #193. Depends on T-5 (above).

Description

Migrate @Presents serverList and @Presents cloudNavigation from AppFeature.State to WindowFeature.State. Actions flow through the WindowFeature scope. As a result, sheets open in the window from which they were triggered, not globally.

Acceptance Criteria

• With multi-window active, the server sheet opens in the key window only, does not block others
• Call sites (File → Connect to Server menu, WelcomeFeature delegate) correctly target the current window
• Existing integration tests for server management flow pass
• CloudNavigation remains functional post-migration
• Build passes, swiftlint lint --strict clean

Module / Layer

Relay / WindowFeature

Complexity

Medium