unikit-implement

Execute the tasks from an already-created feature plan in .unikit/code/plans/ — read the plan manifest (the PLAN.md file in the plan folder), work through the uncompleted tasks in order, write the code, mark progress, and resume across sessions. Supports selective runs by phase or by task numbers, and continuing from where the last session stopped. Use whenever a plan exists and the user wants to build it, e.g.…