Execute implementation plan

Position

This stage implements approved requirements after planning and is also the resume entry point. Its outputs are repository changes, relevant tests, and progress maintained only in sdlc//plan.md.

Inputs and output

• Required inputs: approved spec.md and plan.md; read intent.md when context helps preserve outcome or scope.
• Inspect repository instructions, current state, existing behavior, and available validation evidence before changing code.
• Output: implementation and tests plus an updated existing plan.md. Do not create status, handover, implementation, or validation-report artifacts.

Execution and resume

Determine whether work is new or resumed. On resume, read task statuses and handover, inspect the actual repository, and reconcile discrepancies before continuing. Execute tasks in dependency order, preserve required behavior, and follow existing conventions. Test meaningful milestones and never mark work complete without its defined validation evidence.

Use only pending, in-progress, completed, and locked statuses. Update checklists, validation notes, and this concise section after meaningful milestones, status changes, material validation results, blockers, deviations, or decisions affecting later work: