Use minimal scheme-basic TeX Live install (small, fast, reversible)

Reverts the heavy multi-collection texlive install back toward the
original upstream-Overleaf approach: install-tl with scheme-basic
(~300 MB) plus latexmk and texcount via tlmgr, no docfiles/srcfiles.
This restores the fast, small base image we had before LaTeX support
was added in full.

Tradeoff: documents needing tikz/beamer/siunitx/extra fonts won't
compile out of the box for now — those should stay in Quarto/Typst
until the project is mature enough to justify a full TeX Live.

Made deliberately easy to reverse: a header comment documents that
switching scheme-basic -> scheme-full (one line) restores the complete
toolchain, or individual packages can be appended to the tlmgr list.
Uses TEXDIR=/usr/local/texlive (unversioned) so PATH stays stable
across TeX Live releases.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server-ce/Dockerfile-base

@@ -72,32 +72,39 @@ RUN mkdir -p /opt/quarto-extensions \
 # Install TeX Live (for compiling .tex projects with latexmk)
 # -----------------------------------------------------------------------
 # Verso compiles .qmd with Quarto and .tex with latexmk; both engines live
-# side by side. Rather than (almost) all of texlive-full — which pulls in
-# every CTAN package and takes ~20 min to build — we install a curated set
-# of meta-packages covering the vast majority of real documents: the latex
-# base/recommended/extra collections, recommended fonts, science/math
-# packages, both alternative engines (xetex, luatex), and bibliography
-# tooling. This is a few GB smaller and noticeably faster to build.
+# side by side.
 #
-# If a document needs a package not included here, add the relevant
-# texlive-* collection below (e.g. texlive-fonts-extra, texlive-publishers,
-# texlive-humanities) and rebuild. We deliberately omit inkscape, whose GTK
-# GUI dependency tree is large and only needed for auto SVG->PDF conversion.
+# MINIMAL install (current): the upstream-Overleaf approach — scheme-basic
+# (~300 MB) plus a few essential packages via tlmgr. Fast to build and small.
+# Many documents that need extra packages (tikz, beamer, siunitx, extra
+# fonts, ...) will NOT compile out of the box; users can be told to keep
+# those projects in Quarto/Typst for now.
+#
+# TO GO FULL LATER (when the project is mature): change
+#   selected_scheme scheme-basic  ->  scheme-full
+# and optionally drop the explicit `tlmgr install` line. That single change
+# restores a complete LaTeX toolchain at the cost of size/build time.
+# Alternatively add individual packages to the `tlmgr install` list below.
 # -----------------------------------------------------------------------
-RUN apt-get update \
-&&  apt-get install -y --no-install-recommends \
-      texlive-latex-base \
-      texlive-latex-recommended \
-      texlive-latex-extra \
-      texlive-fonts-recommended \
-      texlive-plain-generic \
-      texlive-science \
-      texlive-xetex \
-      texlive-luatex \
-      texlive-bibtex-extra \
-      texlive-extra-utils \
-      latexmk biber chktex fontconfig python3-pygments \
-&&  rm -rf /var/lib/apt/lists/*
+ARG TEXLIVE_MIRROR=https://mirror.ox.ac.uk/sites/ctan.org/systems/texlive/tlnet
+ENV PATH="${PATH}:/usr/local/texlive/bin/x86_64-linux"
+
+RUN mkdir /install-tl-unx \
+&&  curl -sSL ${TEXLIVE_MIRROR}/install-tl-unx.tar.gz \
+    | tar -xzC /install-tl-unx --strip-components=1 \
+&&  echo "tlpdbopt_autobackup 0"       >> /install-tl-unx/texlive.profile \
+&&  echo "tlpdbopt_install_docfiles 0" >> /install-tl-unx/texlive.profile \
+&&  echo "tlpdbopt_install_srcfiles 0" >> /install-tl-unx/texlive.profile \
+&&  echo "selected_scheme scheme-basic" >> /install-tl-unx/texlive.profile \
+&&  echo "TEXDIR /usr/local/texlive"   >> /install-tl-unx/texlive.profile \
+&&  /install-tl-unx/install-tl \
+      -profile /install-tl-unx/texlive.profile \
+      -repository ${TEXLIVE_MIRROR} \
+&&  /usr/local/texlive/bin/x86_64-linux/tlmgr install \
+      --repository ${TEXLIVE_MIRROR} \
+      latexmk \
+      texcount \
+&&  rm -rf /install-tl-unx
 
 
 # Set up overleaf user and home directory