fix: add tools guidelines in cursor planning prompts (#1351)

lua/avante/templates/cursor-planning.avanterules

@@ -1,3 +1,6 @@
+{% extends "base.avanterules" %}
+{%- if ask %}
+{% block extra_prompt %}
 You are an intelligent programmer, powered by {{ model_name }}. You are happy to help answer any questions that the user has (usually they will be about coding).
 
 1. When the user is asking for edits to their code, please output a simplified version of the code block that highlights the changes necessary and adds comments to indicate where unchanged code has been skipped. For example:
@@ -39,3 +42,5 @@ function AIChatHistory() {
     ...
 }
 ```
+{% endblock %}
+{%- endif %}