[Nit] Integrate first-party compatibility checks into CI

.github/workflows/ci.yml

@@ -173,14 +173,78 @@ jobs:
       - name: Run Tests
         run: uv run --no-sync pytest tests/
 
+  # -------------------------------------------------------------------
+  # First Party Packages
+  # -------------------------------------------------------------------
+
+  test_first_party_packages:
+    name: Test ${{ matrix.repo-name }}
+    needs: check_python_linting
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        repo-name:
+          - tabpfn-extensions
+          - tabpfn-time-series
+    env:
+      TABPFN_MODEL_CACHE_DIR: ${{ github.workspace }}/model_cache
+      HF_TOKEN: ${{ vars.TABPFN_2_5_HF_TOKEN }}
+
+    steps:
+      - name: Checkout TabPFN at current ref
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          path: TabPFN
+
+      - name: Checkout ${{ matrix.repo-name }}
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          repository: PriorLabs/${{ matrix.repo-name }}
+          path: ${{ matrix.repo-name }}
+
+      - name: Set up Python
+        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+        with:
+          python-version: "3.13"
+
+      - name: Set up uv
+        uses: astral-sh/setup-uv@681c641aba71e4a1c380be3ab5e12ad51f415867 # v7.1.6
+
+      - name: Restore model cache
+        id: restore-model-cache
+        uses: actions/cache/restore@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: ${{ github.workspace }}/model_cache
+          key: model-cache-${{ hashFiles('model_cache/**') }}
+          restore-keys: |
+            model-cache-
+          enableCrossOsArchive: true
+        # We don't save the model cache in this workflow as the main CI workflow already
+        # saves it.
+
+      - name: Download models from Hugging Face
+        run: |
+          cd TabPFN
+          uv run python scripts/download_all_models.py
+          cd ..
+
+      - name: Install dependencies and run tests
+        env:
+          FAST_TEST_MODE: 1 # Configures -extensions to run a smaller set of tests.
+        run: |
+          cd ${{ matrix.repo-name }}
+          uv run --with ../TabPFN --all-extras pytest -m "not uses_tabpfn_client"
+
   # -------------------------------------------------------------------
   # GPU: To save compute we only want to execute this workflow once
   # a CPU workflow has passed. Hence, this workflow depends on the
   # ubuntu-latest 3.14 workflow above.
   # -------------------------------------------------------------------
   test_gpu:
     name: Test on GPU
-    needs: test_ubuntu_latest_314
+    needs: 
+      - test_ubuntu_latest_314
 
     strategy:
       fail-fast: false