Client: Mermaid diagrams, drawn by the server

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Dockerfile

@@ -9,8 +9,12 @@ FROM python:3.12-slim
 WORKDIR /App
 COPY Backend/requirements.txt ./
 RUN pip install --no-cache-dir -r requirements.txt
+# Headless Chromium for drawing the desktop client's diagrams (Backend/Diagrams.py).
+RUN playwright install --with-deps --only-shell chromium
 COPY Backend/ ./Backend/
 COPY --from=FrontendBuild /Frontend/dist ./Frontend/dist
+# The same Mermaid the web view uses, for Backend/Diagrams.py.
+COPY --from=FrontendBuild /Frontend/node_modules/mermaid/dist/mermaid.min.js ./Backend/Vendor/mermaid.min.js
 
 WORKDIR /App/Backend
 EXPOSE 8420