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/.editorconfig

@@ -0,0 +1,18 @@
+root = true
+
+[*]
+indent_style = tab
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.coffee]
+indent_style = space
+
+[{package.json,*.yml}]
+indent_style = space
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false