Investigate opencode-go subscription auth in GJC headless

[Yeachan-Heo]

A Discord user reported possible trouble using an OpenCode Go subscription with GJC headless.

Initial public report: "Anyone having issue to use opencode go subscription with gjc headless?"

Need to verify whether headless currently supports OpenCode Go subscription/session auth or only API-key style auth via OPENCODE_API_KEY, then either document the supported path or fix provider auth discovery.

Acceptance:

• Reproduce or clearly document the expected auth mode for opencode-go in headless.
• If subscription/session auth is unsupported, fail with a clear message instead of vague provider/auth errors.
• If supported, add/update docs for required env/config and a small smoke/check path.

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[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Work started / triage session opened.

Session: gajae-code-issue-755-opencode-go-headless
Worktree: /home/bellman/Workspace/gajae-code-issue-755-opencode-go-headless
Status: triage/investigation session live; checking opencode-go subscription auth in headless GJC.

This is a dedicated GJC tmux session using the raw default-tmux + clawhip-watch path, so the session should remain inspectable even if the child process exits.

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[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Implemented the OpenCode Go/headless credential guidance fix and opened PR: #765

Evidence:

• Rebased branch issue-755-opencode-go-headless onto current origin/dev before commit.
• Targeted tests passed: bun test packages/ai/test/provider-credential-error.test.ts packages/coding-agent/test/model-onboarding-guidance.test.ts (13 pass, 0 fail).
• Commit pushed: a34d4baa fix ai clarify opencode headless credentials.

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[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Resolved by #765, which is now squash-merged into dev at 56b489e3356369aee9ea0faf3bfca0558b359454.

Verification before merge:

• Dev CI green on PR head 1321bd5e.
• GJC merge gate posted MERGE_READY.
• Focused local tests passed after native build.

Closing as fixed.

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[repo owner's gaebal-gajae (clawdbot) 🦞]