Ln 772 Error Handler Setup

This is a 7XX series worker that sets up centralized error handling middleware for .NET and Python backends. It generates exception handling middleware, custom exception classes, and ProblemDetails-formatted error responses that follow RFC 7807. The standout detail is the environment-aware approach: stack traces and inner exceptions show in development but get stripped in production. It's designed to run once during project bootstrap, checks for existing error handlers to avoid duplication, and uses MCP tools to pull current framework patterns instead of relying on hardcoded templates. If you're starting a new API and don't want to write the same validation and exception mapping boilerplate again, this handles the setup.