d4d823df45
User-configured metadata on recorder objects (recorders[].metadata in YAML) was silently discarded — MetadataRecordOption existed but was never called anywhere in the codebase, causing plugin (HTTP/gRPC) recorders to always receive null metadata. Fix: wrap recorders that carry config metadata in MetadataRecorder, which auto-appends the metadata to every Record() call. This covers all paths (handler, router, sniffer, service) with zero call-site changes.