Function parse_hibp_response

fn parse_hibp_response(response: &str, target_suffix: &str) -> u32

Parse HIBP API response to find password hash and return breach count.

Response format: “SUFFIX:COUNT\r\n…” (e.g., “0018A45C4D1DEF81644B54AB7F969B88D65:3\r\n…”). Returns the number of times the password appears in breaches (0 if not found).