[DevMando]

Summary

The CLI's Components folder had 56 source files in one flat list, making related UI code harder to find. This PR groups those files into feature folders, following the organization already used by Services.

What changed

• Organize components into Shell, Workspaces, Conversation, Input, Project, Sessions, Settings, Onboarding, and Activity.
• Keep App and its partial class files together in Shell, so their shared state and lifecycle remain easy to follow.
• Add an explicit @namespace MandoCode.Components to moved Razor components. Their type names stay the same, preserving existing component references, tests, and Desktop compatibility.
• Add a component-folder guide and update current README examples, architecture guidance, and the Unreleased changelog.

Why this was done

Developers can now find a feature's components together—for example, prompt and autocomplete components under Input, and workspace tabs and pane layouts under Workspaces. The folder guide also gives future components a clear home.

How it was tested

• All 1,247 CLI tests passed on .NET 10.
• All 1,247 CLI tests passed on .NET 8.
• Desktop built successfully against the reorganized engine with zero warnings and errors.
• Patch whitespace checks passed.

Notes

This is source organization only; it changes no component logic, UI behavior, dependencies, or version numbers. Existing tests cover the relocated components. The local launch-settings edit is excluded, and this PR does not change Desktop's pinned engine revision.