Implement multi-host bindings + write isolation for okf-graph-eng

[RichardHightower]

Parent plan

Tracks: okf-plugin#55 — Plan: Multi-host agent parity + write isolation across the OKF ecosystem

This is Wave A #1. Downstream foundation tickets (PKC, SAC, DEKC, AGER, wiki_ticket_sdd) depend on the contract landed here.

Goal

Make okf-graph-eng install and operate the same way on Claude Code, Grok Build, Codex, Agent Plugins 1.0, Grok Bot, and LangChain Deep Agents — with deterministic identity-bound writes and worktree+PR isolation when writing into a shared second-brain knowledge tree.

Current state

• Dual-host: .claude-plugin/ + .grok-plugin/
• Hooks: hooks/hooks.json (post-edit curate)
• Missing: root Agent Plugins 1.0 plugin.json, .codex-plugin/, docs/GROK_BOT.md, docs/LANG_CHAIN_DEEP_AGENTS.md, docs/ISOLATION.md, docs/ONBOARDING.md, host skill wrappers

Deliverables

Docs

• docs/GROK_BOT.md — identity grok-bot/okf-graph-eng, owned types, isolation, write path
• docs/LANG_CHAIN_DEEP_AGENTS.md — SkillsMiddleware / skills= path
• docs/ISOLATION.md — worktree + PR protocol for OKF bundles
• docs/ONBOARDING.md — LLM-wiki history, destination state, public repo list

Packaging

• Root plugin.json (Agent Plugins 1.0 schema)
• .codex-plugin/plugin.json + Codex-compatible hooks
• Keep .claude-plugin / .grok-plugin working

Runtime

• Author identity guidance on write-adjacent paths
• Session skill/command for isolation (pattern from second-brain-core brain_session.py)
• hosts/grok-bot/SKILL.md and hosts/deep-agents/SKILL.md

Surface

• README multi-host table
• Related plugins list (foundation + ContentPack suite)
• CHANGELOG entry

Tests

• Existing graph validate/pack tests still pass
• Host docs and plugin.json present

Reference

Copy patterns from second-brain-core 0.3.0.

Process

1. Branch from main
2. Implement checklist
3. Open PR that closes this issue and references Plan: Multi-host agent parity + write isolation across the OKF ecosystem #55
4. Human review + explicit OK before merge
5. After merge, unlock downstream Wave A tickets

Non-negotiables

See #55: deterministic writes, identity, isolation, progressive disclosure, privacy (no private remote in public docs), type ownership, skills-first.