A Claude skill that creates three structured spec files (requirements, design, and tasks) before any code is written, giving AI agents a shared source of truth. Use it when starting new features or projects to prevent AI agents from filling gaps with conflicting assumptions across sessions.
- **REQ-001**: Users shall log time entries against a client project.
- _Acceptance_: POST /entries returns 201 with entry id, duration, and project_id
- **REQ-002**: Users shall generate a monthly invoice from logged entries.
- _Acceptance_: GET /invoices/:month returns PDF with line items summing to total