Add dataset download script for Chest X-Ray

This script downloads the Chest X-Ray dataset from Kaggle, unzips it, and cleans up the zip file.

scripts/01_download_dataset.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# Exit immediately if a command exits with a non-zero status
+set -e
+
+echo "🚀 Starting dataset download pipeline..."
+
+# Resolve the absolute path of the project root and dataset directory
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+DATASET_DIR="$PROJECT_ROOT/dataset"
+
+# Ensure the dataset directory exists
+mkdir -p "$DATASET_DIR"
+
+# Install Kaggle CLI if it is not already installed
+if ! command -v kaggle &> /dev/null; then
+    echo "📦 Installing Kaggle CLI..."
+    pip install -q kaggle
+fi
+
+# Ensure the environment variable is set
+if [ -z "$KAGGLE_API_TOKEN" ]; then
+    echo "❌ ERROR: KAGGLE_API_TOKEN is not set."
+    echo "Please run: export KAGGLE_API_TOKEN='your_token_here' before running this script."
+    exit 1
+fi
+
+# Download and unzip
+echo "📥 Downloading Chest X-Ray dataset from Kaggle..."
+kaggle datasets download -d paultimothymooney/chest-xray-pneumonia -p "$DATASET_DIR"
+
+echo "🗜️ Unzipping dataset..."
+unzip -q "$DATASET_DIR/chest-xray-pneumonia.zip" -d "$DATASET_DIR"
+
+echo "🧹 Cleaning up zip archive..."
+rm "$DATASET_DIR/chest-xray-pneumonia.zip"
+
+echo "✅ Dataset successfully downloaded and extracted to: $DATASET_DIR"