Add system dependencies for GRIB processing to Dockerfile

Added required system libraries for ECMWF data processing:
- libeccodes-dev: Core ECMWF GRIB decoding library
- libeccodes-tools: GRIB processing tools
- gfortran: Fortran compiler for GRIB libraries
- libhdf5-dev: HDF5 data format support
- libnetcdf-dev: NetCDF data format support

These dependencies are required for cfgrib and xarray
to properly process ECMWF GRIB weather data files.

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

Co-Authored-By: Claude <noreply@anthropic.com>

Dockerfile

@@ -3,6 +3,15 @@ FROM python:3.11-slim
 # Set working directory
 WORKDIR /app
 
+# Install system dependencies for GRIB processing
+RUN apt-get update && apt-get install -y \
+    libeccodes-dev \
+    libeccodes-tools \
+    gfortran \
+    libhdf5-dev \
+    libnetcdf-dev \
+    && rm -rf /var/lib/apt/lists/*
+
 # Copy requirements file
 COPY requirements.txt .