Function severity_rank 

pub const fn severity_rank(severity: Option<AdvisorySeverity>) -> u8

What: Map advisory severity to a numeric rank for sorting (higher is worse).

Inputs:

• severity: Optional advisory severity value.

Output:

• Numeric rank where larger numbers indicate higher severity (Critical highest).

Details:

• Returns 0 when severity is missing to ensure advisories without severity fall last.
• Keeps ordering stable across both news feed sorting and advisory-specific listings.