feat: Initialize project with basic structure and dependencies

Sets up the foundational elements for the NewsCaster AI application. This includes:
- Initializing the project with Vite and React.
- Defining core types for articles and player state.
- Configuring build tools and TypeScript.
- Adding essential dependencies like React, Vite, and Google's Gemini API client.
- Providing initial README instructions for running locally.
- Setting up basic styling and structure in index.html.
- Defining available voices and playback constants.
- Implementing utility functions for audio handling.

constants.ts

@@ -0,0 +1,15 @@
+import { VoiceName } from './types';
+
+export const AVAILABLE_VOICES = [
+  { name: VoiceName.Puck, label: 'Puck (Male, Standard)' },
+  { name: VoiceName.Charon, label: 'Charon (Male, Deep)' },
+  { name: VoiceName.Kore, label: 'Kore (Female, Soothing)' },
+  { name: VoiceName.Fenrir, label: 'Fenrir (Male, Energetic)' },
+  { name: VoiceName.Zephyr, label: 'Zephyr (Female, Clear)' },
+];
+
+export const MIN_SPEED = 0.5;
+export const MAX_SPEED = 3.5;
+export const SPEED_STEP = 0.5;
+
+export const SAMPLE_RATE = 24000;