refactor: restructure to monorepo with backends and apiTest

- Move web/backend to backends/potter-api
- Move web/frontend to backends/potter-api/frontend
- Add root package.json with npm workspaces
- Update README.md with monorepo navigation
- Update .github/workflows/api-tests.yml for dynamic test discovery
- Update bruno_test_scenario.md paths
- Fix .gitignore to allow JSON data files
- Add three new AI tests in apiTest/PotterAPI/AI/

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

backends/potter-api/frontend/README.md

@@ -0,0 +1,24 @@
+# frontend
+
+## Project setup
+```
+npm install
+```
+
+### Compiles and hot-reloads for development
+```
+npm run serve
+```
+
+### Compiles and minifies for production
+```
+npm run build
+```
+
+### Lints and fixes files
+```
+npm run lint
+```
+
+### Customize configuration
+See [Configuration Reference](https://cli.vuejs.org/config/).