diff --git a/.gitea/docker/Dockerfile.ci-cpp b/.gitea/docker/Dockerfile.ci-cpp
index 34ae917..dca81f3 100644
--- a/.gitea/docker/Dockerfile.ci-cpp
+++ b/.gitea/docker/Dockerfile.ci-cpp
@@ -10,6 +10,7 @@ RUN apt-get update -qq && \
     curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
     apt-get install -y --no-install-recommends \
       nodejs \
+      doxygen \
       cmake \
       build-essential \
       git \
diff --git a/.gitea/workflows/cpp-tests.yml b/.gitea/workflows/cpp-tests.yml
index 05db3ce..f35369d 100644
--- a/.gitea/workflows/cpp-tests.yml
+++ b/.gitea/workflows/cpp-tests.yml
@@ -63,7 +63,12 @@ jobs:
     runs-on: eulernest
     container:
       image: git.eulernest.eu/conformallab/ci-cpp:latest
-      options: "--memory=1400m --memory-swap=1400m"
+      # Memory bumped from 1400m → 1600m to avoid OOM during CGAL header
+      # compilation on ARM64 (CGAL + Eigen templates allocate ~700 MB per
+      # cc1plus instance; -j1 leaves a small margin).
+      # memory-swap == memory disables swap entirely so OOM fails fast
+      # rather than thrashing on the SD card.
+      options: "--memory=1600m --memory-swap=1600m"
 
     steps:
       - uses: actions/checkout@v4
@@ -72,7 +77,7 @@ jobs:
         run: cmake -S code -B build -DWITH_CGAL_TESTS=ON -DCMAKE_BUILD_TYPE=Release
 
       - name: Build CGAL-Tests
-        run: nice -n 19 cmake --build build --target conformallab_cgal_tests -j2
+        run: nice -n 19 cmake --build build --target conformallab_cgal_tests -j1
 
       - name: Run CGAL-Tests
         run: >
diff --git a/.gitea/workflows/doc-build.yaml b/.gitea/workflows/doc-build.yaml
new file mode 100644
index 0000000..dc4216b
--- /dev/null
+++ b/.gitea/workflows/doc-build.yaml
@@ -0,0 +1,56 @@
+name: API Docs
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Doc-build — informational only
+#
+# Generates Doxygen HTML from the public headers and reports warning
+# statistics.  Does NOT block merges: `continue-on-error: true` ensures
+# warnings or extraction issues never fail the CI gate.  When Doxygen
+# coverage is denser (Phase 8c), this job can be promoted to a hard
+# requirement and the HTML deployed to Pages.
+#
+# Note: Gitea Actions on GHES does not support `actions/upload-artifact@v4`,
+# so HTML artifact upload is intentionally omitted.  The warning summary
+# in the job log is the primary reviewer signal; reviewers who want the
+# HTML can rebuild it locally with `cmake --build build --target doc`.
+# ─────────────────────────────────────────────────────────────────────────────
+jobs:
+  doc-build:
+    if: github.event_name == 'pull_request'
+    runs-on: eulernest
+    container:
+      image: git.eulernest.eu/conformallab/ci-cpp:latest
+    continue-on-error: true   # never block the merge
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Generate API documentation
+        run: doxygen Doxyfile 2>&1 | tee doxygen.log
+
+      - name: Summarise warnings
+        if: always()
+        run: |
+          if [ -f doc/doxygen/doxygen-warnings.log ]; then
+            warn=$(wc -l < doc/doxygen/doxygen-warnings.log)
+            echo "DOC ▸ Doxygen warnings: $warn"
+            echo ""
+            echo "First 20 warnings:"
+            head -20 doc/doxygen/doxygen-warnings.log
+          else
+            echo "DOC ▸ No warning log produced — check that Doxyfile WARN_LOGFILE points to doc/doxygen/doxygen-warnings.log"
+          fi
+
+      - name: Report HTML output
+        if: always()
+        run: |
+          if [ -d doc/doxygen/html ]; then
+            files=$(find doc/doxygen/html -type f | wc -l)
+            size=$(du -sh doc/doxygen/html | cut -f1)
+            echo "DOC ▸ HTML output: $files files, $size total"
+          fi