Add GDAL dependencies for PDF map generation on HF

- Install gdal-bin, libgdal-dev for contextily/rasterio
- Set GDAL environment variables for compilation
- Enables OpenStreetMap tile rendering in PDF exports on HF Spaces

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Dockerfile

@@ -4,12 +4,20 @@ FROM python:3.11-slim
 # Set working directory
 WORKDIR /app
 
-# Install system dependencies
+# Install system dependencies including GDAL for contextily/maps
 RUN apt-get update && apt-get install -y \
     build-essential \
     curl \
+    gdal-bin \
+    libgdal-dev \
+    python3-gdal \
     && rm -rf /var/lib/apt/lists/*
 
+# Set GDAL environment variables
+ENV GDAL_CONFIG=/usr/bin/gdal-config
+ENV CPLUS_INCLUDE_PATH=/usr/include/gdal
+ENV C_INCLUDE_PATH=/usr/include/gdal
+
 # Copy requirements
 COPY requirements.txt .