Force Docker rebuild for web search dependencies

Increment CACHEBUST to force fresh build with duckduckgo-search,
beautifulsoup4, and lxml packages. Add example web client

Dockerfile

@@ -11,7 +11,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 # Clone and build llama.cpp with MINIMAL optimizations (fast build)
 WORKDIR /build
-ARG CACHEBUST=3
+ARG CACHEBUST=4
 RUN git clone https://github.com/ggerganov/llama.cpp.git && \
     cd llama.cpp && \
     cmake -B build -DCMAKE_BUILD_TYPE=Release \