Implement registered agent participants: Hermes, Codex, Claude Code, OpenCLAW, GitHub, CI, MCP

[mdheller]

Agent work order

@copilot @codex please implement this after PR #1 lands or by branching from seed/agentterm-chatops-core if instructed.

Goal

Add participant adapters for Hermes, Codex, Claude Code, OpenCLAW, GitHub, CI, and MCP with Agent Registry gating.

Required invariant

No non-human participant may be enabled from local config alone. AgentTerm must resolve identity, session state, grants, and revocation status through Agent Registry before dispatch.

Required scope

• Add participant adapter skeletons behind AgentTermAdapter.
• Add pre-dispatch Agent Registry resolution checks.
• Add Policy Fabric admission checks for mutations, shell/test execution, sensitive context release, tool use, and CI retries.
• Preserve agent_id, registry ref, grant IDs, session ID, adapter key, Matrix room/thread, workroom, topic scope, policy refs, and evidence refs.
• For Codex/Claude Code: model repo work as branch/PR/diff/test events, not hidden local edits.
• For GitHub/CI: model bot actions as agent events where they act autonomously.
• For MCP: require explicit tool grants.
• Add fake backend tests; do not require live external CLIs/services in CI.

Non-goals

• Do not add provider-specific SDKs directly to cli.py.
• Do not execute local shell commands as agents without registry and policy gates.
• Do not grant ambient MCP access.

Validation

ruff check .
pytest