docs: update project-structure.md

docs/src/project-structures/project-structure.md

@@ -51,7 +51,10 @@ order: 1
 │  │  ├─ index.html - Root static index loaded by Electron renderer process
 │  └─ └─ main.ts - Renderer process entry point
 ├─ tests/ - Application test configuration
-│  └─ app.spec.ts - Test file specification
+│  ├─ results/ - Where to save PlayWright test result files and screenshots
+│  ├─ specs/ - PlayWright test spec file
+│  ├─ fixtures.ts - Test common execution API
+│  └─ testUtil.ts - Test utilities
 ├─ .editorconfig - Editor recommended configuration file for IDE
 ├─ .eslintignore - List of files to be ignored by ESLint
 ├─ .eslintrc.json - ESLint rule configurations