Reorganize: Move all skills to skills/ folder

- Created skills/ directory
- Moved 272 skills to skills/ subfolder
- Kept agents/ at root level
- Kept installation scripts and docs at root level

Repository structure:
- skills/           - All 272 skills from skills.sh
- agents/           - Agent definitions
- *.sh, *.ps1       - Installation scripts
- README.md, etc.   - Documentation

Co-Authored-By: Claude <noreply@anthropic.com>

skills/plugins/marketplaces/design-plugins/design-and-refine/scripts/cleanup-check.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+# Design Variations Plugin - Cleanup Check Script
+# This runs on session end to check for leftover temporary files
+
+# Check if .claude-design directory exists in current project
+if [ -d ".claude-design" ]; then
+    echo "[Design Variations] Warning: Temporary design files found in .claude-design/"
+    echo "[Design Variations] Run '/design-variations:cleanup' to remove them, or delete manually."
+fi
+
+# Check for leftover route files (Next.js)
+if [ -d "app/__design_lab" ] || [ -d "app/__design_preview" ]; then
+    echo "[Design Variations] Warning: Temporary route directories found in app/"
+fi
+
+if [ -f "pages/__design_lab.tsx" ] || [ -f "pages/__design_preview.tsx" ]; then
+    echo "[Design Variations] Warning: Temporary route files found in pages/"
+fi
+
+exit 0