Remove static tex files, simplify Dockerfile and build workflow

- Remove brevetkarte.tex (unused static demo, superseded by template)
- Dockerfile: remove unnecessary COPY, workspace is volume-mounted at runtime
- Makefile: remove build-front, default target is now build-personalized
- README: remove references to removed files and targets

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -7,12 +7,4 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     make \
     && rm -rf /var/lib/apt/lists/*
 
-# Set working directory
-WORKDIR /workspace
-
-# Copy project files
-COPY brevetkarte.tex .
-COPY cyclist-logo.png .
-
-# Default command
-CMD ["pdflatex", "-interaction=nonstopmode", "brevetkarte.tex"]
+WORKDIR /workspace