chore: update project state and prepare for image support development

- Add comprehensive image test document with various image types
- Update project structure with development artifacts
- Prepare foundation for image support enhancement phase
- Include test files for validating image editing workflows

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

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

node_modules/is-arrayish/index.js

@@ -0,0 +1,10 @@
+'use strict';
+
+module.exports = function isArrayish(obj) {
+	if (!obj) {
+		return false;
+	}
+
+	return obj instanceof Array || Array.isArray(obj) ||
+		(obj.length >= 0 && obj.splice instanceof Function);
+};