This reverts:
- 28b03595b research: delete Hono backend (do not merge) (#25667)
- b24a4e897 chore(server): clean up post-Hono-deletion scar tissue (#26542)
v1.14.42 broke startup for users with plugins that depend on the
Hono wire format (most visibly opencode-gemini-auth, see #26546).
Restoring Hono as the default backend on stable channels while we
investigate the actual plugin compatibility story.
OPENCODE_EXPERIMENTAL_HTTPAPI flag and dual-backend selection come
back. Stable installs default to Hono; dev/beta default to HTTP API.
Conflict resolution: took the pre-deletion side for control-plane
schemas and the seven test files where post-deletion follow-up PRs
had also touched the conflicting lines. The HTTP API code added
since the deletion (compression, cors-vary, fence, lifecycle log,
account error mapping, etc.) is preserved as-is — those still apply
on the HTTP API path for users on dev/beta channels.
Moves effect logging, observability, runtime utilities, flags, installation
version info, and process utilities from opencode to core package. This
enables better code sharing across packages and establishes core as the
single source of truth for foundational utilities.
All internal imports updated to use @opencode-ai/core paths for consistency.
