Function render_recovery_html 

pub fn render_recovery_html(parts: RecoveryEmailParts<'_>) -> String

Render the framework’s polished HTML body for a recovery / magic-link email. The visual treatment matches DESIGN_CHROME.md: calm typography, a single brand-accent point of emphasis (the CTA button), hairline separation, table-based layout for email- client compatibility, inlined CSS for clients that strip <style> blocks, and a @media query for mobile readability.

Inputs are pre-validated by the caller. The function does no HTML-escaping on intro or fine_print — those are framework- owned strings, never user-supplied. cta_url is escaped because it contains the reset token which is base64 (safe but belt-and-braces).