Perplexity AI launches Portable Computer on-device AI agent  SiliconANGLE Perplexity partners with Nvidia to launch Portable Computer, a fully local AI agent with zero token costs  Venturebeat Perplexity launches AI tool that runs locally and seeks permission for cloud help  Firstpost Perplexity’s on-device AI offering promises data control and lower token costs  Computerworld Perplexity Ships Portable Computer on NVIDIA DGX Spark: Local Harness, OS-Enforced Sandbox, and Zero Per-Token Cost for Local Steps  MarkTechPost