fix: add libgtk-3-0t64 for Camoufox browser (Debian 13 package name diff)

backend/Dockerfile

@@ -3,16 +3,18 @@ FROM python:3.11-slim
 
 WORKDIR /app
 
-# System libs: build tools for wheels, libgomp for onnxruntime (chromadb), + Playwright browser deps
+# System libs: build tools for wheels, libgomp for onnxruntime (chromadb), + Playwright/Camoufox browser deps
 RUN apt-get update && apt-get install -y --no-install-recommends \
         build-essential \
         libgomp1 \
+        libgtk-3-0t64 \
+        libgdk-pixbuf-2.0-0 \
     && rm -rf /var/lib/apt/lists/*
 
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
-# Install Playwright (Camoufox) browser + system deps
+# Install Playwright (Camoufox) browser binary
 RUN playwright install chromium && playwright install-deps chromium
 
 COPY . .