Function render_claude_style 

pub fn render_claude_style(intent: &StageIntent) -> String

Render a StageIntent as the legacy Claude/OpenCode slash-command text.

This is the byte-identical renderer: Claude and OpenCode produce exactly what stage_prompt produced before the migration (CONTEXT D-01 zero regression). It lives here — not in the adapters — so the two agents cannot drift apart, and the per-stage snapshot tests pin it.