kata-move-phase

Purpose: Enable flexible phase reorganization (cross-milestone moves and within-milestone reordering). Output: Phase moved/reordered, directories renamed, ROADMAP.md updated, STATE.md updated, git commit as historical record.

Supported operations:

• Cross-milestone move: /kata-move-phase 3 to v1.6.0
• Reorder within milestone: /kata-move-phase 3 before 1 or /kata-move-phase 3 after 1

<execution_context> @.planning/ROADMAP.md @.planning/STATE.md </execution_context>