Add multi-layer gateway integration for Hermes agent:

• Enhanced gateway skill (v0.7.0) with auth-error-focused description that triggers on NOT_AUTHENTICATED and credential errors
• Skip hook for Hermes (doesn't support Claude Code-style hooks)
• transform_tool_result plugin to intercept auth errors at runtime and append credential stub creation instructions to tool results
• Docker env injection (proxy URLs via docker_env) and CA cert mounting (docker_volumes) for containerized tool execution
• Universal gateway skill at ~/.onecli/skills/ for unknown agents with ONECLI_GATEWAY and ONECLI_GATEWAY_SKILL_PATH env vars
• agent_framework query param on GetGatewaySkill API for per-agent skill content (hook-based vs broad description)