Devcontainer

This is a diagnostic framework for fixing slow or broken devcontainer setups. It walks through six states from no containerization to validated environments, with specific interventions for each problem: slow startups get Dockerfile caching advice, configuration errors get compatibility checklists, and multi-service setups get compose templates. The core insight is that every choice affects startup time and team onboarding, so it forces you to make those tradeoffs explicit. Includes analyzer scripts and templates for common patterns. Use this when your container takes five minutes to start or works locally but breaks in Codespaces. Skip it if you're writing application code or dealing with production deployments.