Fix Windows desktop window controls with native decorations

[PabloValencia14]

What & why

Closes #2589

On Windows, the main window was transparent and undecorated, using macOS-like custom controls and manual dragging. Existing VM probing limited the native fallback. This change uses a native, opaque, decorated main window on Windows, preserves the Linux native frame and canvas workaround and macOS custom chrome, removes obsolete Windows VM shell probes, keeps chrome visibility and rounded clipping consistent, and updates screen-height guidance and minimal Windows launch documentation.

Linked issue

Closes #2589

Checklist

• This PR addresses an accepted issue (linked above) — issue Windows desktop uses custom macOS-like controls and resizes incorrectly across monitors #2589 is newly filed and awaiting maintainer acceptance.
• I wrote or personally reviewed every line of this change
• I tested it on Android and/or Desktop (say which, and how) — Desktop (Windows): :desktopApp:compileKotlinJvm passed; launched the actual desktop app and confirmed the UI and functionality; exercised native window/client geometry and DPI transitions across three displays at 96, 120, and another differing DPI, including resize, maximize, and restore. No Android testing. Rendered Compose pixels were not individually checked. AI assistance was used; I personally reviewed every line of this change.

[github-actions]

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