Add NativeAOT entry point for the dotnet CLI

[JeremyKuhne]

Introduce a three-layer AOT architecture to enable near-instant startup for common CLI commands while preserving full managed CLI functionality:

• dn.exe (src/Cli/dn): NativeAOT host that resolves DOTNET_ROOT and hostfxr, marshals args, and calls into dotnet-aot via P/Invoke. Includes dn-native-debug.vcxproj for native debugging in VS.

• dotnet-aot.dll (src/Cli/dotnet-aot): NativeAOT shared library that tries an AOT-compiled parser for simple commands (--version, --info), then falls back to hosting the full managed CLI via hostfxr.

• dotnet.dll (src/Cli/dotnet): Existing managed CLI, wrapped with #if CLI_AOT conditional compilation to share source files with the AOT build while keeping full functionality in the managed path.

Supporting changes:

• Add hostfxr interop APIs to Microsoft.DotNet.NativeWrapper (init, run_app, close, get_runtime_delegate, set_runtime_property_value)
• Fix hostfxr_get_dotnet_environment_info return type to StatusCode
• Add VS Code tasks and launch config for building/debugging AOT
• Add DESIGN.md documenting architecture, build, and debugging workflow

[Copilot]

Pull request overview

This PR introduces an experimental NativeAOT-based entry point for the SDK CLI (dn) that can handle a small set of fast-path commands in AOT, and otherwise hosts/runs the existing managed CLI as a fallback.

Changes:

• Add new NativeAOT projects for dn (exe) and dotnet-aot (NativeAOT shared library) plus design/debugging documentation.
• Extend Microsoft.DotNet.NativeWrapper hostfxr interop surface (and fix hostfxr_get_dotnet_environment_info return type).
• Add VS/VS Code workspace, tasks, and solution wiring for building/debugging the new AOT layers.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
tasks.code-workspace	Adds VS Code tasks + a native debug launch profile for dn AOT.
start-code.cmd	Allows launching a specific .code-workspace, defaults to tasks.code-workspace.
src/Resolvers/Microsoft.DotNet.NativeWrapper/NETBundlesNativeWrapper.cs	Updates environment-info interop call to use StatusCode.
src/Resolvers/Microsoft.DotNet.NativeWrapper/Microsoft.DotNet.NativeWrapper.csproj	Adds InternalsVisibleTo for dotnet-aot.
src/Resolvers/Microsoft.DotNet.NativeWrapper/Interop.cs	Adds hostfxr hosting APIs and adjusts environment-info return type.
src/Cli/dotnet/Program.cs	Adds CLI_AOT conditional entry point for shared-source AOT build.
src/Cli/dotnet/Parser.cs	Adds minimal AOT parser under CLI_AOT plus conditional compilation split.
src/Cli/dotnet/CommandLineInfo.cs	Adjusts output/logic to support AOT compilation path.
src/Cli/dotnet-aot/dotnet-aot.csproj	New NativeAOT shared-library project linking shared CLI sources.
src/Cli/dotnet-aot/NativeEntryPoint.cs	New unmanaged export entry point implementing fast-path vs fallback dispatch.
src/Cli/dotnet-aot/ManagedHost.cs	New hostfxr-based managed-host fallback implementation.
src/Cli/dotnet-aot/DESIGN.md	Architecture/design/build/debug documentation for the three-layer approach.
src/Cli/dn/dn.csproj	New NativeAOT dn host project + VS debugging helper generation.
src/Cli/dn/dn-native-debug.vcxproj	New VS-native-debug “stub” project for reliable AOT breakpoint binding.
src/Cli/dn/Program.cs	New dn host that resolves DOTNET_ROOT/hostfxr and calls into dotnet-aot.
src/Cli/dn/.gitignore	Ignores machine-specific generated debug artifacts.
sdk.slnx	Adds the new CLI projects to the main solution.
cli.slnf	Adds the new CLI projects to the CLI solution filter.

[baronfel]

/ba-g known issue around macos communication to redhat/quay servers

[NikolaMilosavljevic]

SDK directory resolution gap in managed fallback path

In src/Cli/dn/Program.cs (line 24), sdkDir is set to AppContext.BaseDirectory — the directory where dn.exe lives (e.g., .dotnet/). This value is passed to NativeEntryPoint.ExecuteCore, which constructs the managed fallback path as:

\\csharp
string dotnetDll = Path.Join(sdkDir, "dotnet.dll"); // NativeEntryPoint.cs:58
\\

However, dotnet.dll doesn't live next to dn.exe — it lives in a version-specific SDK subdirectory (e.g., .dotnet/sdk/11.0.100-preview.3.26170.106/dotnet.dll). The native dotnet muxer resolves this via hostfxr_resolve_sdk2, but dn currently skips that step.

As a result, the managed fallback path (when DOTNET_CLI_ENABLEAOT is unset or false) always fails with:
\
The managed fallback could not be located. Expected '/dotnet.dll'...
\\

This doesn't affect the AOT fast path (--version, --info), but it means any command that needs the managed CLI (e.g., build, test, run) will fail even when a full SDK is installed.

Suggested fix: Use hostfxr_resolve_sdk2 (or equivalent logic) to resolve the actual SDK version directory before passing sdkDir to dotnet_execute.

@JeremyKuhne