Use python3 as the canonical command name course-wide (#104) (#105)

modules/22-securing-third-party-mcp-and-skills/README.md

@@ -265,14 +265,14 @@ normal question) and the attacker (you plant content the agent reads).
 
    ```bash
    cd ~/ai-workflow-course/tasks-app
-   python cli.py add "$(cat ~/ai-workflow-course/modules/22-securing-third-party-mcp-and-skills/lab/poisoned-task.txt)"
-   python cli.py list
+   python3 cli.py add "$(cat ~/ai-workflow-course/modules/22-securing-third-party-mcp-and-skills/lab/poisoned-task.txt)"
+   python3 cli.py list
    ```
 
    `poisoned-task.txt` contains a normal-looking task followed by an injected instruction (a fake
    "system" directive telling the assistant to reveal local secrets / run a command and hide it).
 
-2. **Be the victim.** Paste the full output of `python cli.py list` into your agent's chat (Claude
+2. **Be the victim.** Paste the full output of `python3 cli.py list` into your agent's chat (Claude
    Code in these examples; sub your own) and ask the thing you'd actually ask: *"Here's my task list,
    summarize what's pending and tell me what to
    work on first."* Watch what happens. Depending on the model, it may flag the injection, or it may
@@ -303,7 +303,7 @@ normal question) and the attacker (you plant content the agent reads).
 
    ```bash
    # the "tool" the agent is allowed to call in read-only mode
-   python cli.py list          # works
+   python3 cli.py list          # works
    # the tool it is NOT exposed (a write); in a least-privilege setup this path is simply absent
    ```