feat(agents): add grok adapter

[yyovil]

Adds the grok harness (xAI Grok CLI), stacked on the agent platform (#119).

• Adapter package + Constructors() registration + resolver test.
• Reuses the claude-code activity deriver (grok installs Claude Code-compatible hooks).

🤖 Generated with Claude Code

Stack

1. feat(agents): agent platform — registry, activity hooks, harness allowlist #119
2. feat(agents): add grok adapter #120 👈 current
3. feat(agents): add droid adapter #121
4. feat(agents): add amp adapter #122
5. feat(agents): add agy adapter #123
6. feat(agents): add crush adapter #124
7. feat(agents): add aider adapter #125
8. feat(agents): add cursor adapter #126
9. feat(agents): add qwen adapter #127
10. feat(agents): add copilot adapter #128
11. feat(agents): add goose adapter #129
12. feat(agents): add auggie adapter #130
13. feat(agents): add continue adapter #131
14. feat(agents): add devin adapter #132
15. feat(agents): add cline adapter #133
16. feat(agents): add kimi adapter #134
17. feat(agents): add kiro adapter #135
18. feat(agents): add kilocode adapter #136
19. feat(agents): add vibe adapter #137
20. feat(agents): add pi adapter #138
21. feat(agents): add autohand adapter #139

[greptile-apps]

Greptile Summary

This PR adds a Grok Build (xAI) agent adapter alongside registration in the adapter registry and a resolver test. Since Grok has a documented zero-config Claude Code compatibility layer, the implementation consciously delegates hook installation to claudecode.Plugin.GetAgentHooks, reuses the ao hooks claude-code <event> dispatch path, and reads the same ports.MetadataKey* constants for SessionInfo.

• New grok.Plugin satisfies both adapters.Adapter and ports.Agent; uses -p for prompt delivery and -r for session restore via a hook-captured native session ID.
• GetAgentHooks delegates entirely to claudecode.Plugin, writing hooks that fire as ao hooks claude-code <event> so the existing CLI dispatcher handles them with zero additional routing code.
• Grok is registered in registry.Constructors() and the daemon wiring test verifies HarnessGrok resolves to manifest ID \"grok\".

Confidence Score: 5/5

Safe to merge; the change is an isolated new adapter with no effect on existing adapters or shared state.

The grok adapter is entirely additive: it adds a new package, a single line to the registry, and one entry to the wiring test. The delegation to claudecode.Plugin.GetAgentHooks is safe because that method is stateless with respect to the Plugin struct. Session metadata keys are sourced from the exported ports.Metadata* constants, matching the same constants used in claudecode.SessionInfo, so there is no hidden string coupling. Binary resolution, permission-mode mapping, and restore logic follow the same patterns as the existing adapters.

No files require special attention.

Important Files Changed

Filename	Overview
backend/internal/adapters/agent/grok/grok.go	New grok adapter implementing the full ports.Agent interface; binary resolution, permission-mode mapping, hook delegation to claudecode, and session restore are all well-structured and consistent with existing adapters.
backend/internal/adapters/agent/grok/grok_test.go	Good unit-test coverage: manifest, config spec, prompt strategy, launch command (all permission modes), restore command (with and without session ID), SessionInfo (populated and empty), and hook delegation smoke-test.
backend/internal/adapters/agent/registry/registry.go	Minimal, correct one-line registration of grok.New() in Constructors(); no issues.
backend/internal/daemon/wiring_test.go	Adds {domain.HarnessGrok, "grok"} to the resolver table test; straightforward and correct.

_{Reviews (2): Last reviewed commit: "feat(agents): add grok adapter" | Re-trigger Greptile}