Add JSDoc headers to scripts and improve sync-manifest tool

.gitignore

@@ -1,3 +1,39 @@
-\.DS*
+# Claude temporary files
+tmpclaude-*
+
+# Node.js
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+package-lock.json
+yarn.lock
+
+# Build outputs
+dist/
+build/
+out/
+
+# IDE and editors
+.vscode/
+.idea/
 *.swp
-/.idea/
+*.swo
+*~
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+logs/
+
+# Environment files
+.env
+.env.local
+.env.*.local
+
+# Coverage
+coverage/
+.nyc_output/