Update MCP server template

[jeffkl]

Fixes #6560

This updates the MCP server template to have some new guidance particularly to use a self-contained, single file executable. It also allows for users to specify that they want to use AOT via a command-line argument.

Option	Default Value
--framework	net9.0
--self-contained	true
--aot	false

The matrix of possible values for some MSBuild properties is a little complicated, this table explains how certain arguments affect them:

Option	RuntimeIdentifiers	PublishSelfContained	PublishSingleFile	PublishAot	RollForward
--self-contained:true	✅	✅	✅	❌	❌
--self-contained:false	❌	❌	❌	❌	✅
--aot:true	✅	✅	✅	✅	❌

And the default values for RuntimeIdentifers is:

• win-x64
• win-arm64
• osx-arm64
• linux-x64
• linux-arm64
• linux-musl-x64

Microsoft Reviewers: Open in CodeFlow

[joelverhagen]

CC @baronfel, @jeffhandley, @timheuer, @MackinnonBuck

[Copilot]

Pull Request Overview

This PR updates the MCP server template to provide better guidance for users, particularly around creating self-contained, single-file executables. The update adds command-line options for users to specify framework targets, self-containment, and AOT compilation settings.

• Adds support for --framework, --self-contained, and --aot command-line arguments with appropriate defaults
• Updates project configuration to generate self-contained single-file executables by default
• Includes conditional MSBuild properties based on template arguments for different deployment scenarios

Reviewed Changes

Copilot reviewed 22 out of 22 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Multiple snapshot test files	Updated to reflect new template output with self-contained configurations
McpServerSnapshotTests.cs	Added test methods for new template argument scenarios
README.md	Enhanced documentation explaining self-contained vs framework-dependent deployment
McpServer-CSharp.csproj.in	Updated MSBuild properties with conditional logic for different deployment modes
template.json	Added new parameter symbols for framework, AOT, and self-contained options
ide.host.json	Made new template parameters visible in IDE
dotnetcli.host.json	Configured CLI parameter names and visibility

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