cultcache-rs: the header canary checks for the quoted header, not a prefix

"cultcache.store.v" is a prefix of the "cultcache.store.v1" the refusal names,
so the unquoted check failed on a correct refusal.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/cultcache-rs/src/lib.rs

@@ -5184,7 +5184,7 @@ mod tests {
             if echoed {
                 assert!(text.contains(&format!("\"{header}\"")), "{text}");
             } else {
-                assert!(!text.contains(header), "{text}");
+                assert!(!text.contains(&format!("\"{header}\"")), "{text}");
                 assert!(!text.contains("SECRET"), "{text}");
                 assert!(text.contains(&format!("of {} bytes", header.len())), "{text}");
             }