v0.21.0

• Make --version/-V always emit a structured protocol-v1 version event (JSON by default, or --output yaml|plain/--json), dropping the conventional plain-text form so version output follows the same protocol as every other CLI result
• Extend the version payload to carry name alongside version, plus an optional human-facing display_name and an opaque caller-supplied build identifier such as a git commit SHA, each omitted when absent
• Teach the version pre-parser to recognize the caller's own value-taking global flags — from the clap command in Rust, an explicit value-flags list in Go/Python/TypeScript — so a flag's value like --stdout-file is never mistaken for the subcommand boundary that would hide a following --version
• Land the redesign identically across Rust, Go, Python, and TypeScript at API parity, and update the normative spec's version-output section to match