sync: update from private repo (f6d625db)

Dockerfile

@@ -52,6 +52,10 @@ FROM node:22-bookworm-slim AS runtime
 #  - xvfb/x11vnc/websockify: the noVNC display stack (display_mode: novnc) that
 #    powers the Browser tab live view, InteractiveBrowse, and the CAPTCHA pool
 #  - fonts-*: legible text (incl. CJK) in the headed browser / screenshots
+#  - libreoffice-impress: headless .pptx/.ppt -> PDF conversion for the file-
+#    preview feature (office-preview.ts). The PDF is then rasterised to PNG via
+#    the pre-baked PyMuPDF (fitz). --no-install-recommends keeps the image lean
+#    (skips the GUI/java extras); CJK glyphs come from the fonts-noto-cjk above.
 RUN apt-get update && apt-get install -y --no-install-recommends \
     git \
     ca-certificates \
@@ -65,6 +69,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     websockify \
     fonts-liberation \
     fonts-noto-cjk \
+    libreoffice-impress \
     && rm -rf /var/lib/apt/lists/*
 
 # Pre-bake python packages into the system site-packages (read-only bind-mounted