Show HN: Agentic interface for mainframes and COBOL

Hypercubic is launching Hopper, an agentic development environment for mainframes, to bring AI tools to the mainframe and COBOL world. Mainframes still run critical infrastructure in banking, payments, insurance, and more. Hopper combines a real TN3270 terminal, mainframe-aware panels, and an AI agent to operate inside the mainframe environment.