Skill: integrate-worktrees

Purpose

Closes out a batch of worktrees from the main repo: scan all active linked worktrees, let the user pick which to land, verify all picks are clean, merge and push each in sequence, then remove all successfully-merged worktrees together. Eliminates the need to cd into each worktree directory and invoke a per-branch delivery.

Core Objective

Primary goal: From the main repo on the main branch, land the user-selected worktree branches onto main, deliver them to origin, and clean up succeeded ones — leaving the repository in a known-clean state.

Success Criteria (all must be satisfied):