fix(api): compile header *value* regexp for scope rules

SetScope compiled rule.Header.Key twice, so a scope rule's header
**value** pattern was silently ignored and replaced by the key pattern.
Scope drives which traffic is shown/logged/intercepted, so this caused
incorrect matching: rules meant to match on a header value matched on the
header key instead, both missing intended in-scope traffic and including
unintended traffic.

Author: MrEchoFi

pkg/api/resolvers.go

@@ -300,7 +300,7 @@ func (r *mutationResolver) SetScope(ctx context.Context, input []ScopeRuleInput)
 				return nil, fmt.Errorf("invalid header key in scope rule: %w", err)
 			}
 
-			headerValue, err = stringPtrToRegexp(rule.Header.Key)
+			headerValue, err = stringPtrToRegexp(rule.Header.Value)
 			if err != nil {
 				return nil, fmt.Errorf("invalid header value in scope rule: %w", err)
 			}