Move architecture, package structure, dependencies, and implementation
rules into .opencode/agent/implementor.md (default primary agent). Add
.opencode/agent/reviewer.md (read-only primary agent) with PR review
workflow that leaves inline review comments only -- no issue creation,
no edits, no commits. AGENTS.md is now the shared context both agents
load: workflow, git/PR conventions, and docs index. Set
default_agent: implementor in opencode.json.
Achmad Setyabudi Susilo