[gerardogrisolini]

Adds ZenCODE, an open-source (MIT) coding agent written in Swift. zen --acp runs it over stdio; it is already listed on https://agentclientprotocol.com/get-started/agents.

Disclosure: I'm the author.

• Binary distribution for macOS arm64 from the v3.1.0 GitHub Release: a single executable, SHA-256 pinned.
• No Linux or Windows entry for now. Since v3.1.0 the Linux release archives link the Swift runtime dynamically, so they would not start on a machine without Swift 6.4 installed, and I'd rather not list a build that fails to launch. I'll add Linux back in a follow-up PR once there is a self-contained build. Because of this, the auth check on the Ubuntu runner will report ZenCODE as skipped ("No build for linux-x86_64").
• Auth: when the client declares _meta["terminal-auth"], initialize advertises a terminal auth method (zencode-setup) that runs zen without --acp to open the interactive provider and sign-in setup.
• Icon: 16×16 monochrome, currentColor only.

Happy to adjust anything.