T-11: Window → Open Projects dynamic list

[kirich1409]

Part of EPIC #193. Depends on #201.

Description

Add a dynamic list of open project windows to CommandGroup(after: .windowList), sourced from AppFeature.State.windows. Clicking an entry dispatches openWindow(value: projectID), which SwiftUI resolves to the existing window.

Acceptance Criteria

• The list updates in real time as project windows open and close
• Clicking an entry activates the existing window rather than creating a duplicate
• The currently focused project is marked (checkmark or bold)
• Welcome-only windows appear under a separate section or are omitted

Module / Layer

Relay / RelayApp commands

Complexity

Medium