Fix dump1090 not found in Docker by building from source

The dump1090 packages are not available in Debian slim repos, causing
the Docker build to silently skip installation. This builds dump1090-fa
from FlightAware's source repository instead.

Fixes #46

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -35,13 +35,28 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     procps \
     && rm -rf /var/lib/apt/lists/*
 
-# Install dump1090 for ADS-B (package name varies by distribution)
-RUN apt-get update && \
-    (apt-get install -y --no-install-recommends dump1090-mutability || \
-     apt-get install -y --no-install-recommends dump1090-fa || \
-     apt-get install -y --no-install-recommends dump1090 || \
-     echo "Note: dump1090 not available in repos, ADS-B features limited") && \
-    rm -rf /var/lib/apt/lists/*
+# Build dump1090-fa from source (packages not available in slim repos)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    git \
+    pkg-config \
+    libncurses-dev \
+    && cd /tmp \
+    && git clone --depth 1 https://github.com/flightaware/dump1090.git \
+    && cd dump1090 \
+    && make \
+    && cp dump1090 /usr/bin/dump1090-fa \
+    && ln -s /usr/bin/dump1090-fa /usr/bin/dump1090 \
+    && cd /app \
+    && rm -rf /tmp/dump1090 \
+    # Cleanup build tools to reduce image size
+    && apt-get remove -y \
+        build-essential \
+        git \
+        pkg-config \
+        libncurses-dev \
+    && apt-get autoremove -y \
+    && rm -rf /var/lib/apt/lists/*
 
 # Copy requirements first for better caching
 COPY requirements.txt .