Add Gemini CLI render adapter with opt-in agents list

[kelos-bot]

Summary

Adds Gemini CLI as a third render adapter alongside Codex and Claude, and introduces an opt-in top-level agents: list so new adapters do not change existing render/apply behavior.

Configs without agents: still render exactly the existing default set: codex and claude. Users can opt in to Gemini with:

version: 1
agents: [codex, claude, gemini]

Changes

• Add AgentGemini, config validation for agents:, and --agent gemini support.
• Refactor adapter selection through a name-based registry with backward-compatible defaults.
• Add a render-only geminiAdapter:
  • instructions -> GEMINI.md
  • MCP servers and hooks -> .gemini/settings.json
  • skills -> .gemini/skills/<name>/
• Keep Gemini import as a harmless no-op for this first render-only increment.
• Document Gemini and the agents: opt-in list in the README.
• Add regression tests for default codex+claude rendering, Gemini opt-in rendering, explicit Gemini rendering, and unknown agent validation.

Closes #7

Testing

• make verify
• make test

Add a Gemini CLI render adapter and a top-level `agents:` opt-in list. Existing configs without an `agents:` key continue to render only Codex and Claude.

[kelos-bot]

/kelos review

[gjkim42]

/kelos review

[kelos-bot]

🤖 Kelos Task Status

Task kanon-reviewer-issue-comment-dc976956178b has succeeded. ✅

[kelos-bot]

Review Summary

Verdict: COMMENT (approve blocked — cannot approve own PR; no blocking issues found)
Overall correctness: patch is correct
Scope: Adds a render-only Gemini CLI adapter plus an opt-in top-level agents: list; existing configs without agents: keep rendering only codex+claude.

Findings Overview

Priority	Count	File:Line	Summary
P0	0	—	none
P1	0	—	none
P2	0	—	none
P3	2	internal/core/gemini.go:41	Confirm Gemini CLI's settings.json hooks shape matches the reused Claude-style structure
P3		internal/core/gemini_test.go:30	Default-excludes test asserts no gemini file but not that codex+claude still render

Findings

The backward-compatibility contract is the core risk here, and it is handled correctly: adaptersFor defaults to defaultAgents (codex+claude) when cfg.Agents is empty and only widens the set when the user opts in, with a dedicated regression test (TestRenderDefaultsExcludeGemini). The Gemini render path mirrors claudeAdapter exactly (instructions → GEMINI.md, MCP+hooks → settings.json, skills → .gemini/skills), MCP httpUrl/url SSE distinction and ${VAR} env-header expansion are consistent with the Claude adapter, validation of agents:/targets: entries is wired through the shared IsAgent helper, and the import no-op merges harmlessly. CLI help and README are updated for the new surface. No correctness, security, or convention issues found.

Suggestions (optional)

• [P3] internal/core/gemini.go:41 — The hooks block reuses hooksForAgent, which emits Claude's nested event -> [{matcher, hooks:[{type,command,...}]}] structure. Worth confirming Gemini CLI's settings.json hooks schema actually accepts that exact shape; if it differs, the rendered hooks would be silently ignored by Gemini. Render-only, so not blocking, but a quick confirmation against Gemini's config docs would be good.
• [P3] internal/core/gemini_test.go:30 — TestRenderDefaultsExcludeGemini verifies no gemini file is emitted, but does not assert that codex+claude files are still rendered by default. Adding that positive assertion would fully lock the default-set contract.

Key takeaways

• Opt-in agents: mechanism and default-set preservation are correctly implemented and tested — the back-compat trap from #7 is avoided.
• Only non-blocking nits: verify the Gemini hooks schema and strengthen the default-set test.

[gjkim42]

/kelos pick-up
origin/main is updated.

[kelos-bot]

🤖 Kelos Task Status

Task kanon-pr-responder-issue-comment-f491e871c97c has succeeded. ✅

[kelos-bot]

🤖 Kelos Agent @gjkim42

/kelos review

[kelos-bot]

🤖 Kelos Agent @gjkim42

Rebased onto origin/main and addressed the remaining review suggestion by strengthening the default adapter regression test to assert Codex and Claude still render when agents: is absent. I also verified the Gemini hooks shape against current Gemini CLI docs, updated the PR body, and confirmed CI is passing (build, test, verify, labels, CLA). Ready for human re-review.