gstack-sprint

<Purpose> gstack-sprint wraps the 3-Phase Sprint workflow (design→execute→review) as a structured skill to guarantee deterministic execution. Without this skill, the 3-Phase workflow exists only as prompt instructions in boss.md and may be forgotten during long sessions. This skill is the single entry point for end-to-end feature implementation — it coordinates design, execution, and review with user confirmation at each phase boundary. </Purpose> <Use_When> - End-to-end feature implementation ("build this feature", "design it and implement it") - Build or Mid-sized intent type with implementation phase included - User says "sprint", "end-to-end", "e2e implementation" </Use_When> <Do_Not_Use_When> - Pure design/planning/idea review without implementation → use /office-hours or /plan-ceo-review directly - Architecture intent type (design only, no build) - "just design it", "just plan it", "review my idea" — these route to /office-hours or /plan-ceo-review - Single-purpose requests: code review → /review, QA → /qa, deploy → /ship - Trivial fixes, research, documentation </Do_Not_Use_When> <Why_This_Exists> End-to-end feature work fails silently in three predictable ways: 1. Implementation starts before design is aligned — wrong thing built 2. Execution proceeds without structured iteration — partial implementations declared done 3. Review skips comparison against the design doc — drift goes unnoticed gstack-sprint enforces the three-phase contract: user-confirmed design → a...