Bootstrap a new immutable SDD repo by copying a starter from the plugin into the current directory. Detects empty vs existing repo, helps select mode (spec / app / single) + team language + profile handling, copies the matching starter, and emits next-step git commands. Use when starting a new immutable SDD project or adding immutable configuration to an existing project. Triggers - "/immutable:init", "immutable 시작", "SDD 부트스트랩", "새 spec 레포".
