Add skill: puzzle-activity-planner

[fruitwyatt]

Adds a puzzle activity planner skill for planning puzzle-based activities.

What it does:

• Plans multi-puzzle sessions for classrooms, parties, team-building, and events
• Generates pre-configured links with URL params for one-click ready-to-use puzzles
• Covers word search, crossword, sudoku, bingo, and jigsaw

Use case: Teachers planning classroom activities, parents organizing party games, event organizers creating team-building sessions.

Skill repo: https://github.com/fruitwyatt/puzzle-activity-planner