feat: WordPress plugin versioning + heatmap fix + dynamic latest download

- Add VERSION file (1.5.4) for tracking WP plugin version
- Update plugin headers to 1.5.4 (cannaiq-menus.php, crawlsy-menus.php)
- Add dynamic /downloads/cannaiq-menus-latest.zip route that auto-redirects
  to highest version (no manual symlinks needed)
- Update frontend download links to use -latest.zip
- Fix StateHeatmap.tsx to parse API values as numbers (fixes string concat bug)
- Document versioning rules in CLAUDE.md

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wordpress-plugin/build-plugin.sh

@@ -36,9 +36,16 @@ zip -r "${OUTPUT_DIR}/${OUTPUT_FILE}" . \
     -x "assets/css/crawlsy-menus.css" \
     -x "assets/js/crawlsy-menus.js"
 
+# Create/update the "latest" symlink
+cd "${OUTPUT_DIR}"
+rm -f cannaiq-menus-latest.zip
+ln -s "${OUTPUT_FILE}" cannaiq-menus-latest.zip
+
 echo ""
 echo "Build complete!"
 echo "  File: ${OUTPUT_DIR}/${OUTPUT_FILE}"
 echo "  Size: $(ls -lh "${OUTPUT_DIR}/${OUTPUT_FILE}" | awk '{print $5}')"
 echo ""
-echo "Download URL: https://cannaiq.co/downloads/cannaiq-menus-${VERSION}.zip"
+echo "Download URLs:"
+echo "  Versioned: https://cannaiq.co/downloads/cannaiq-menus-${VERSION}.zip"
+echo "  Latest:    https://cannaiq.co/downloads/cannaiq-menus-latest.zip"