CVE-2026-59877: protobufjs: Denial of Service via infinite loop in .proto option parsing

protobufjs parsed option names by advancing through schema tokens until it reached an = token, without checking for end of input. A crafted .proto schema that opens an option declaration but ends prematurely could cause the option parser to loop without ever terminating.

This affects the reflection parsing path (parse, Root.load, Root.loadSync).