API docs parity: .NET

## .NET API Docs

**Parent epic:** #1653

**Doc format:** [XML documentation comments](https://learn.microsoft.com/dotnet/csharp/language-reference/xmldoc/) (`/// `, ``, ``, etc.). The compiler emits a `.xml` file alongside the assembly.

**Culture:** **Strong and enforced.** NuGet packages conventionally include the XML doc file in the package (IDE IntelliSense reads it). Microsoft's own libraries always ship it. Roslyn analyzers can warn on missing docs.

**Hosting analogues:**

| Service | How it works |
|---------|-------------|
| ~~[fuget.org](https://www.fuget.org/)~~ | ⚠️ **Defunct** — DNS no longer resolves as of 2026-06-13. Was the closest analogue to javadoc.io for NuGet packages |
| [NuGet package page](https://www.nuget.org/) | Shows README, not full API surface |
| [DocFX](https://dotnet.github.io/docfx/) | Microsoft's Sphinx-equivalent generator; many projects self-host output on GitHub Pages |

> **Note on fuget.org:** fuget.org was the only third-party service that automatically rendered API docs from NuGet packages (analogous to javadoc.io). As of 2026-06-13 it is completely offline — DNS does not resolve. This means there is **no automatic, zero-config API docs host** for .NET packages. Self-hosted DocFX output (e.g. GitHub Pages from CI) is the only viable option.

**Key difference from Java:** The XML doc file ships *inside* the `.nupkg` (analogous to javadoc jar living in Maven Central), so IDEs can consume it without separate publication. But NuGet doesn't *mandate* it the way Maven Central does, and with fuget.org gone, there is no hosted equivalent to javadoc.io for .NET.

Start by reviewing the .NET API surface covered by this parity issue and the repository's existing documentation approach. The issue specifies XML documentation comments and discusses NuGet packaging and DocFX, but names no files, tests, or exact API scope. Done would require an agreed .NET documentation scope and a documented way to produce or publish the API reference.

Written by the indexing model from the issue text.