Test coverage for pure utility functions:
- isValidPrivateOrigin: validates private network origins (security)
- normalizeForwardedProto: normalizes ws/wss to http/https for proxies
- sanitizeValue: handles NaN/Inf values in JSON data
- cloneMetadata/cloneMetadataValue: deep copies metadata maps/slices
- cloneAlert/cloneAlertData: deep copies alert structures
Coverage increased from 20.9% to 37.3% (80 test cases).
