Sync Ai Now Skill Prompts

Update the server-side AI Now skill prompt injection file.

Backend-owned AI Now sessions read this file when preparing their agent spec, so web/mobile/remote clients must sync it to the backend, not only to a client-local Tauri filesystem.

curl -X POST "http://127.0.0.1:14242/agent/ai-now/skill-prompts" \  -H "Content-Type: application/json" \  -d '{}'

{}

{
  "detail": [
    {
      "loc": [
        "string"
      ],
      "msg": "string",
      "type": "string",
      "input": null,
      "ctx": {}
    }
  ]
}