Add configuration files and update project structure

- Added `.gitignore`, `host.json`, and `requirements.txt` to `genaipgraphics/`
- Added configuration files and test setup for `tests/`:
  - `babel.config.js`
  - `jest.config.js`
  - `package-lock.json`
  - `package.json`
  - Updated `README.md`
- Added `astro.config.mjs` to `webapp/config/`

README.md

@@ -298,6 +298,13 @@ genaipgraphics/
 │   ├── .gitignore
 │   ├── host.json
 │   └── requirements.txt
+├── tests/
+│   ├── babel.config.js
+│   ├── chat.test.js
+│   ├── jest.config.js
+│   ├── package-lock.json
+│   ├── package.json
+│   └── README.md
 ├── webapp/
 │   ├── config/
 │   │   ├── astro.config.mjs