[NFC] Opencode architect and submit agent definitions

[jasnell]

Working on a more detailed architect agent definition for opencode integration. The architect agent focuses on high-level design, code structure, and maintainability. It is similar to the plan agent but with specific emphasis on our coding practices, conventions, patterns, and architectural principles.

I originally had this defined as a local claude agent and have been using it successfully while going through streams api improvements/refactors. Figured it would be worth sharing.

• Architect Agent (primary) ... Used for planning, brainstorming, reviewing complex code changes, organizing complex refactors, etc. Allowed only to create markdown planning files in the docs/planning directory. Similar to the built-in Plan agent only with more targeted understanding of the project, our conventions, our priorities for review, etc. Press tab to select it.

• Submit Agent (subagent) ... Can be used to check if the current branch is ready to submit as a PR or update a PR. Trigger it with prompts like, "Is this branch ready to submit?" ... It will perform a number of checks on the PR including whether is has been rebased on main, whether linting/formatting has been done, makes recommendations on multi-commit organization; if a PR has been opened already, checks to see if CI has run or if outstanding PR comments have been resolved or not, etc.

• The CLAUDE.md is also updated with additional context. You can ask opencode things like, "I want to update v8" and it'll find the v8-update.md instructions then help you walk through them. Likewise, you can ask it for help setting up the vscode environment correctly and it'll walk you through that also.

[npaun]

This is really nice and detailed. Has this prompt been working well for you in practice so far?

[npaun]

In addition to this super-specific workerd architect agent, I wonder if it'd be useful to have a more generic agent for when we work on other repos. Its prompt would have all the same stuff about good engineering practices, but not the workerd implementation details.

[jasnell]

For the "more generic agent" ... there is a port of the claude GSD framework available for opencode internally. That serves the general purpose rather well.