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`.

services/audioUtils.ts

@@ -0,0 +1,66 @@
+import { LiveServerMessage, Modality } from "@google/genai";
+
+// Convert Float32Array (Web Audio API) to PCM Int16 (Gemini API requirement)
+export function floatTo16BitPCM(float32Array: Float32Array): ArrayBuffer {
+  const buffer = new ArrayBuffer(float32Array.length * 2);
+  const view = new DataView(buffer);
+  let offset = 0;
+  for (let i = 0; i < float32Array.length; i++) {
+    let s = Math.max(-1, Math.min(1, float32Array[i]));
+    s = s < 0 ? s * 0x8000 : s * 0x7FFF;
+    view.setInt16(offset, s, true); // Little Endian
+    offset += 2;
+  }
+  return buffer;
+}
+
+// Base64 encoding for the payload
+export function arrayBufferToBase64(buffer: ArrayBuffer): string {
+  let binary = '';
+  const bytes = new Uint8Array(buffer);
+  const len = bytes.byteLength;
+  for (let i = 0; i < len; i++) {
+    binary += String.fromCharCode(bytes[i]);
+  }
+  return btoa(binary);
+}
+
+// Convert Base64 string back to Uint8Array
+export function base64ToUint8Array(base64: string): Uint8Array {
+  const binaryString = atob(base64);
+  const len = binaryString.length;
+  const bytes = new Uint8Array(len);
+  for (let i = 0; i < len; i++) {
+    bytes[i] = binaryString.charCodeAt(i);
+  }
+  return bytes;
+}
+
+// Decode raw PCM data from Gemini to AudioBuffer
+export async function decodeAudioData(
+  data: Uint8Array,
+  ctx: AudioContext,
+  sampleRate: number = 24000,
+  numChannels: number = 1,
+): Promise<AudioBuffer> {
+  // Ensure the byte length is even for Int16Array
+  if (data.byteLength % 2 !== 0) {
+      console.warn("Received odd byte length for PCM16 audio, trimming last byte.");
+      data = data.subarray(0, data.byteLength - 1);
+  }
+
+  // Use the underlying buffer, but handle offsets if the Uint8Array is a view
+  const dataInt16 = new Int16Array(data.buffer, data.byteOffset, data.byteLength / 2);
+  
+  const buffer = ctx.createBuffer(numChannels, dataInt16.length / numChannels, sampleRate);
+
+  for (let channel = 0; channel < numChannels; channel++) {
+    const channelData = buffer.getChannelData(channel);
+    // Determine step size if multiple channels (usually 1 for this API)
+    for (let i = 0; i < dataInt16.length; i++) {
+      // Normalize Int16 to Float32 [-1.0, 1.0]
+      channelData[i] = dataInt16[i] / 32768.0;
+    }
+  }
+  return buffer;
+}