Focus local lab deployment on Linux and WSL

ansible/playbooks/down.yml

@@ -140,22 +140,6 @@
         - courseware_down_ollama_marker.stat.exists
       failed_when: false
 
-    - name: Stop courseware-managed Ollama macOS app if running
-      command: pkill -x Ollama
-      when:
-        - ansible_system == "Darwin"
-        - courseware_down_ollama_marker.stat.exists
-      changed_when: false
-      failed_when: false
-
-    - name: Uninstall courseware-managed Ollama Homebrew formula
-      command: brew uninstall ollama
-      when:
-        - ansible_system == "Darwin"
-        - courseware_down_ollama_marker.stat.exists
-      changed_when: false
-      failed_when: false
-
     - name: Remove managed Unsloth path
       file:
         path: "{{ ansible_env.HOME }}/.unsloth"