Fix nDPI protocol analyzer compilation

Properly link required libraries (json-c, pthread, math) and fail build if compilation fails instead of silencing the error.

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

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

Dockerfile

@@ -49,14 +49,15 @@ RUN echo "=== Searching for nDPI files ===" && \
     echo "=== Checking pkg-config ===" && \
     pkg-config --cflags libndpi 2>/dev/null || echo "pkg-config failed"
 
-# Try multiple compilation approaches, create fallback if all fail
-RUN (gcc -o protocol_analyzer protocol_analyzer.c $(pkg-config --cflags --libs libndpi) -lpcap) || \
-    (gcc -o protocol_analyzer protocol_analyzer.c -I/usr/local/include -L/usr/local/lib -lndpi -lpcap) || \
-    (gcc -o protocol_analyzer protocol_analyzer.c -I/usr/include -L/usr/lib -lndpi -lpcap) || \
-    (echo "nDPI compilation failed, creating fallback analyzer" && \
-     echo '#!/bin/bash' > protocol_analyzer && \
-     echo 'echo "{\"protocol\":\"Unknown\",\"category\":\"Generic\",\"confidence\":0}"' >> protocol_analyzer && \
-     chmod +x protocol_analyzer)
+# Fix nDPI compilation with proper linking order and paths
+RUN echo "=== Attempting nDPI compilation ===" && \
+    ldconfig && \
+    pkg-config --cflags --libs libndpi && \
+    gcc -o protocol_analyzer protocol_analyzer.c \
+        -I/usr/local/include -L/usr/local/lib \
+        -lndpi -lpcap -ljson-c -lpthread -lm \
+    && echo "✅ nDPI compilation successful" \
+    || (echo "❌ nDPI compilation failed with exit code $?" && exit 1)
 
 # Compile the application
 RUN dart compile exe lib/main.dart -o waylume_server