diff --git a/.gitea/docker/Dockerfile.ci-cpp b/.gitea/docker/Dockerfile.ci-cpp
index d9278a1..34ae917 100644
--- a/.gitea/docker/Dockerfile.ci-cpp
+++ b/.gitea/docker/Dockerfile.ci-cpp
@@ -2,6 +2,8 @@ FROM --platform=linux/arm64 ubuntu:22.04
 
 # Node.js 20 from NodeSource (Ubuntu Jammy ships v12 which is too old
 # for actions/checkout@v4 — static class blocks require Node.js >= 16).
+#
+# libboost-dev  — header-only Boost required by CGAL 6.x (-DWITH_CGAL=ON)
 RUN apt-get update -qq && \
     apt-get install -y --no-install-recommends \
       curl ca-certificates && \
@@ -11,6 +13,7 @@ RUN apt-get update -qq && \
       cmake \
       build-essential \
       git \
+      libboost-dev \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /workspace
diff --git a/.gitea/workflows/cpp-tests.yml b/.gitea/workflows/cpp-tests.yml
index 5a55840..84ee042 100644
--- a/.gitea/workflows/cpp-tests.yml
+++ b/.gitea/workflows/cpp-tests.yml
@@ -6,10 +6,16 @@ on:
       - main
       - dev
       - "claude/**"
+      - "feature/**"
   pull_request:
 
+# ─────────────────────────────────────────────────────────────────────────────
+# Job 1 — test-fast
+#   Pure-math tests (Clausen, ImLi₂, Hyper-ideal Geometrie).
+#   Kein CGAL, kein Boost. Läuft auf ALLEN Branches in < 1 s.
+# ─────────────────────────────────────────────────────────────────────────────
 jobs:
-  test:
+  test-fast:
     runs-on: eulernest
     container:
       image: git.eulernest.eu/conformallab/ci-cpp:latest
@@ -17,10 +23,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Configure (tests-only mode)
+      - name: Configure (tests-only)
         run: cmake -S code -B build -DCMAKE_BUILD_TYPE=Release
 
-      - name: Build test binary
+      - name: Build
         run: cmake --build build --target conformallab_tests -j$(nproc)
 
       - name: Run tests
@@ -29,7 +35,7 @@ jobs:
           --output-on-failure
           --output-junit test-results.xml
 
-      - name: Show test summary
+      - name: Zusammenfassung
         if: always()
         run: |
           if [ -f test-results.xml ]; then
@@ -37,5 +43,56 @@ jobs:
             failed=$(grep -o 'failures="[0-9]*"' test-results.xml | grep -o '[0-9]*' | head -1)
             skipped=$(grep -o 'skipped="[0-9]*"' test-results.xml | grep -o '[0-9]*' | head -1)
             passed=$(( ${total:-0} - ${failed:-0} - ${skipped:-0} ))
-            echo "TOTAL: ${total:-0} | PASSED: $passed | FAILED: ${failed:-0} | SKIPPED: ${skipped:-0}"
+            echo "FAST  ▸ TOTAL ${total:-0} | PASSED $passed | FAILED ${failed:-0} | SKIPPED ${skipped:-0}"
+          fi
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Job 2 — test-cgal
+#   Vollständige CGAL-Test-Suite (Phase 3–7, 158 Tests).
+#   Läuft nur auf main, dev und Pull Requests — nicht auf Feature-Branches.
+#   Startet erst nach erfolgreichem test-fast.
+#
+#   Boost-Install-Schritt: solange das Docker-Image noch kein libboost-dev
+#   enthält, wird es hier zur Laufzeit nachinstalliert (~15 s).
+#   Nach dem nächsten Image-Rebuild (Dockerfile bereits aktualisiert) wird
+#   dieser Schritt zum No-Op.
+# ─────────────────────────────────────────────────────────────────────────────
+  test-cgal:
+    needs: test-fast
+    if: >
+      github.ref == 'refs/heads/main' ||
+      github.ref == 'refs/heads/dev'  ||
+      github.event_name == 'pull_request'
+    runs-on: eulernest
+    container:
+      image: git.eulernest.eu/conformallab/ci-cpp:latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Boost installieren (Übergang bis Image-Rebuild)
+        run: apt-get update -qq && apt-get install -y --no-install-recommends libboost-dev
+
+      - name: Configure (WITH_CGAL)
+        run: cmake -S code -B build -DWITH_CGAL=ON -DCMAKE_BUILD_TYPE=Release
+
+      - name: Build CGAL-Tests
+        run: cmake --build build --target conformallab_cgal_tests -j$(nproc)
+
+      - name: Run CGAL-Tests
+        run: >
+          ctest --test-dir build
+          -R "^cgal\."
+          --output-on-failure
+          --output-junit cgal-results.xml
+
+      - name: Zusammenfassung
+        if: always()
+        run: |
+          if [ -f cgal-results.xml ]; then
+            total=$(grep -o 'tests="[0-9]*"'     cgal-results.xml | grep -o '[0-9]*' | head -1)
+            failed=$(grep -o 'failures="[0-9]*"' cgal-results.xml | grep -o '[0-9]*' | head -1)
+            skipped=$(grep -o 'skipped="[0-9]*"' cgal-results.xml | grep -o '[0-9]*' | head -1)
+            passed=$(( ${total:-0} - ${failed:-0} - ${skipped:-0} ))
+            echo "CGAL  ▸ TOTAL ${total:-0} | PASSED $passed | FAILED ${failed:-0} | SKIPPED ${skipped:-0}"
           fi