feat(docker): dodaj weryfikację uruchomienia extensiona

- Skrypt sprawdza czy extension rzeczywiście się zainstalował
- Wyświetla czytelny komunikat sukcesu z info o procesach
- Capture output web-ext do /tmp/web-ext.log dla weryfikacji
- Timeout 30s na instalację extensiona
- Pokazuje PID Firefox i Xvfb

Weryfikacja pokazuje:
✓ Extension installed: rentgen@internet-czas-dzialac.pl
✓ Firefox ESR running in headless mode
✓ Xvfb running on display :99

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

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

Dockerfile

@@ -73,10 +73,48 @@ FROM builder AS runtime
 RUN apt-get update && apt-get install -y \
     firefox-esr \
     xvfb \
+    procps \
     && rm -rf /var/lib/apt/lists/*
 
 # Set display for Xvfb
 ENV DISPLAY=:99
 
-# Start Xvfb and run extension in Firefox
-CMD Xvfb :99 -screen 0 1024x768x24 & npm run ext-test
+# Create startup script with verbose logging and verification
+RUN echo '#!/bin/bash\n\
+set -e\n\
+echo "Starting Xvfb on display :99..."\n\
+Xvfb :99 -screen 0 1024x768x24 &\n\
+XVFB_PID=$!\n\
+sleep 2\n\
+\n\
+echo "Xvfb started with PID: $XVFB_PID"\n\
+echo "Starting web-ext run with verbose logging..."\n\
+echo "========================================"\n\
+\n\
+# Run web-ext with verbose logging and capture output\n\
+npx web-ext run --verbose 2>&1 | tee /tmp/web-ext.log &\n\
+WEBEXT_PID=$!\n\
+\n\
+# Wait for extension installation confirmation\n\
+echo "Waiting for extension to install..."\n\
+for i in {1..30}; do\n\
+    if grep -q "Installed /app as a temporary add-on" /tmp/web-ext.log 2>/dev/null; then\n\
+        echo "========================================"\n\
+        echo "✓ SUCCESS: Extension installed!"\n\
+        echo "✓ Firefox is running in headless mode"\n\
+        echo "✓ Extension: rentgen@internet-czas-dzialac.pl"\n\
+        echo "✓ Process info:"\n\
+        ps aux | grep -E "(firefox|Xvfb)" | grep -v grep | head -3\n\
+        echo "========================================"\n\
+        echo "Extension is ready. Press Ctrl+C to stop."\n\
+        break\n\
+    fi\n\
+    sleep 1\n\
+done\n\
+\n\
+# Keep container running and show logs\n\
+wait $WEBEXT_PID\n\
+' > /app/start.sh && chmod +x /app/start.sh
+
+# Start script
+CMD ["/app/start.sh"]