docs: clarify single-file output constraints in spec, design, and task commands

feat: add task ID support to review hook commit workflow

feat: add design command for generating high-level architecture documentation

feat: add task-based workflow with interactive review hook

feat: add commit command for generating conventional commit messages with emoji prefixes

feat: add review command for structured code review against approved specs

docs: add core workflow documentation for feature development process

feat: add _plans directory with .gitkeep for tracking planning documents

feat: add loc-stats script for counting lines of code by file type

feat: add spec command for generating feature specifications from ideas