Add NuGet installation instructions for schost to all documentation

The schost tool is published to nuget.org as SharpConsoleUI.Host but
the docs only showed the from-source installation method. Add
`dotnet tool install -g SharpConsoleUI.Host` as the primary install
method in README.md, tools/schost/README.md, and docs/SCHOST.md.

Author: nickprotop

README.md

@@ -82,7 +82,15 @@ cd MyApp && dotnet run
 
 ### Desktop Distribution (schost)
 
-Package your app so end users can double-click to launch — no terminal knowledge required:
+Package your app so end users can double-click to launch — no terminal knowledge required.
+
+Install schost from NuGet:
+
+```bash
+dotnet tool install -g SharpConsoleUI.Host
+```
+
+Then use it:
 
 ```bash
 # Initialize terminal config for your project

docs/SCHOST.md

@@ -31,22 +31,30 @@ This is NOT a custom rendering driver. Apps use the real terminal, real `NetCons
 
 ## Installation
 
-schost lives in `tools/schost/` inside the ConsoleEx repository. Run it directly:
+Install from NuGet (recommended):
+
+```bash
+dotnet tool install -g SharpConsoleUI.Host
+```
+
+Then use `schost` directly from anywhere.
+
+### Alternative: from source
+
+If you're working from the ConsoleEx repository, you can run it directly:
 
 ```bash
 dotnet run --project tools/schost/src/schost -- <command>
 ```
 
-Or install as a global .NET tool:
+Or build and install locally:
 
 ```bash
 cd tools/schost
 dotnet pack src/schost -c Release
 dotnet tool install --global --add-source src/schost/nupkg SharpConsoleUI.Host
 ```
 
-Then use `schost` directly from anywhere.
-
 ## Quick Start
 
 ### New project

tools/schost/README.md

@@ -4,13 +4,19 @@ A CLI tool that launches SharpConsoleUI apps in a configured terminal and packag
 
 ## Install
 
+From NuGet (recommended):
+```bash
+dotnet tool install -g SharpConsoleUI.Host
+```
+
+From source:
 ```bash
 cd tools/schost
 dotnet pack src/schost -c Release
 dotnet tool install --global --add-source src/schost/nupkg SharpConsoleUI.Host
 ```
 
-Or run directly:
+Or run directly without installing:
 ```bash
 dotnet run --project src/schost -- <command>
 ```