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/@jridgewell/trace-mapping/src/strip-filename.ts

@@ -0,0 +1,8 @@
+/**
+ * Removes everything after the last "/", but leaves the slash.
+ */
+export default function stripFilename(path: string | undefined | null): string {
+  if (!path) return '';
+  const index = path.lastIndexOf('/');
+  return path.slice(0, index + 1);
+}