️ Code Action — Insert Diagram as Comment

On every [ResultFlow] method with a detectable chain a single-click code action inserts the Mermaid diagram as a /* ... */ block comment directly above the method — no build required:

/*
```mermaid
flowchart LR
    N0_EnsureAsync["EnsureAsync"]:::gatekeeper
    N0_EnsureAsync -->|pass| N1_BindAsync
    ...
```*/
[ResultFlow]
public async Task<Result<UserDto>> RegisterAsync(RegisterCommand cmd) => ...

The ```mermaid fence renders the diagram inline in VS Code, GitHub, Rider, and other Markdown-aware IDEs — no external tool needed. This is done by the companion analyzer (REF002).