Replace the flat "read, implement, test, commit" workflow in muse/coder.md with a 5-phase orchestration pattern (prep → design → implement → audit → commit). The coder agent now spawns focused sub-agents for each phase via the Agent tool, with phase-specific tool restrictions and iteration logic (implement ↔ audit loop with 3-cycle cap). Development guidelines section updated to match current body reference files, adding mypy, uv/make update, worktree development, test-apps/ test-only/coverage commands, and other previously missing content.