opencode v1.18.34: namespaced session headers, re-signed macOS binaries

opencode v1.18.34 shipped on September 30, 2026 — a small release aimed at request identity and macOS trust.

What changed

• Model requests now carry namespaced session and parent-session identity headers, giving providers a consistent way to attribute traffic to a session and its parent.
• Locally compiled macOS binaries are re-signed after compilation so they run reliably on macOS 27+.
• The macOS CLI release binaries are signed with a Developer ID.

Three community contributors are credited, including the darwin re-signing fix and a correction to GPT 6.1 Sol cache pricing in the Zen docs.