Lupin 0.2.2: lupin update and agents --wire

Two follow-ups to 0.2.1's agent routes, both asked for in review:

• lupin update (ADR-49): one command from "there is a newer Lupin" to "everything on this machine runs it". Registry check (only when you invoke it, never a startup phone-home), npm i -g lupin-code@latest with npm's own output, and, when a lupin-tui sidecar is on your PATH and a Rust toolchain exists, the sidecar is rebuilt to the matching version from the TUI sources the package now ships and replaced only on build success. No sidecar, no offer; no cargo, the manual command is printed.
• lupin agents ... --wire (ADR-48): the last manual step of subagent routing gone. set <name> --profile <p> --wire writes model: claude-lupin-agent:<name> into the agent's definition file (project .claude/agents first, then home; frontmatter name: match first, filename fallback); unset <name> --wire restores inherit. The one deliberate exception to "Lupin never touches your harness": explicit flag, that single field, old value printed, every other byte preserved, no frontmatter block means refusal, and built-in agents (no file) are named as out of reach: for those the blanket subagents route is the lever.

Full changelog: https://github.com/Fanfulla/Lupin/blob/main/CHANGELOG.md