Complete software development toolkit: spec-driven workflows, autonomous orchestration, lifecycle management (bugfix/modify/refactor), quality validation, and performance monitoring. v3.5.0: 5th core workflow (modify) + README simplification (670→400 lines) + comprehensive docs (COMMANDS.md, SETUP.md, FEATURES.md). v3.4.0: Confidence-based auto-execution. v3.3.9: MANDATORY/ALWAYS directive descriptions.