Feature: MCP tools should support remote daemons (cross-host agent management)

[shouwangzhe]

Core problem

Paseo MCP tools only operate on the local daemon. There is no concept of a host parameter at the MCP layer. This means:

• Desktop UI cannot see or interact with remote agents
• Agents cannot manage other agents on remote daemons via MCP
• Subagent tracking does not work cross-host
• The only way to interact with remote daemons is through the CLI --host flag, which is a workaround

Current state

Layer	Local daemon	Remote daemon
CLI	✅	✅ (--host)
MCP tools	✅	❌
Desktop UI	✅	❌
Subagent track	✅	❌

Proposal

Add an optional host parameter to MCP tools (create_agent, list_agents, send_agent_prompt, get_agent_status, etc.) so they can target a remote daemon (via relay offer URL or direct TCP).

This would unlock:

1. Desktop UI showing remote agents — the client already renders agents from MCP; once MCP can reach remote daemons, the UI follows naturally
2. Cross-host agent orchestration via MCP — agents can spawn/monitor/communicate with agents on other machines without shelling out to CLI
3. Unified subagent tracking — parent agents can track children regardless of which host they run on
4. Consistent permission model — remote operations go through the same MCP permission layer as local ones

Use case

Handing off tasks to a GPU/XPU server for compute-heavy work (training, inference, profiling) while maintaining the same interactive experience as local agents — real-time output, follow-up prompts, status tracking, all from the local desktop client.

Environment

• Paseo desktop app on macOS
• Remote daemon connected via relay (prelay.baidu.com:80)
• Relay offer URL: https://paseoapp.baidu.com/#offer=...