feat: Initialize project structure

Sets up the basic project configuration for Cognitive Clarity. This includes:
- Initializing `package.json` with necessary dependencies (React, Gemini API, Lucide React) and build scripts for Vite.
- Creating a basic `index.html` with Tailwind CSS and Google Fonts integration.
- Setting up `index.tsx` as the React application entry point.
- Configuring `tsconfig.json` for TypeScript compilation with Vite.
- Establishing `vite.config.ts` for development server setup and environment variable handling.
- Adding a standard `.gitignore` file.
- Updating `README.md` with local run instructions and AI Studio links.
- Defining `metadata.json` for application details.
- Creating core type definitions in `types.ts`.
- Populating `constants.ts` with initial CBT glossary terms.
- Adding utility functions for audio processing in `services/audioUtils.ts`.

index.tsx

@@ -0,0 +1,15 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import App from './App';
+
+const rootElement = document.getElementById('root');
+if (!rootElement) {
+  throw new Error("Could not find root element to mount to");
+}
+
+const root = ReactDOM.createRoot(rootElement);
+root.render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);