fix: parseAgents() ignores 'args' field in ~/.acpx/config.json agents config

[log-li]

Summary

When configuring an agent with command and args fields in ~/.acpx/config.json:

{
  "agents": {
    "cursor": {
      "command": "/home/logan/.local/bin/agent",
      "args": ["acp"]
    }
  }
}

The args array is silently ignored. Only the command field is read. This causes the spawned agent to run without the intended arguments, leading to protocol initialization failures.

Root Cause

In src/config.ts, parseAgents() only reads raw.command and discards raw.args:

function parseAgents(value: unknown, sourcePath: string): Record<string, string> | undefined {
  ...
  for (const [name, raw] of Object.entries(value)) {
    ...
    const command = raw.command;
    // raw.args is never read!
    parsed[normalizeAgentName(name)] = command.trim();
  }
}

The config schema accepts {command, args} but the runtime code ignores args.

Impact

• Custom agent commands that require arguments (e.g., Cursor CLI with agent acp) silently fail
• The agent process starts but without the correct subcommand, causing ACP protocol initialization to hang
• The schema shows args as supported in acpx config show, but the field has no effect

Expected Behavior

parseAgents() should merge command and args into the final command string, e.g.:

const fullCommand = raw.args && raw.args.length > 0
  ? `${raw.command.trim()} ${raw.args.join(" ")}`
  : raw.command.trim();
parsed[normalizeAgentName(name)] = fullCommand;

Workaround

Put the full command (including args) in the command field as a single string:

{
  "agents": {
    "cursor": {
      "command": "/home/logan/.local/bin/agent acp"
    }
  }
}

Environment

• acpx version: 0.3.1, 0.4.0, latest main
• OS: Linux (WSL2)
• Node.js: v22.22.0