Update the system prompt to call out the ability to run commands.

Author: daxian-dbw

shell/agents/AIShell.OpenAI.Agent/Helpers.cs

@@ -195,7 +195,7 @@ internal static class Prompt
     internal static string SystemPromptWithConnectedPSSession = $"""
         You are a virtual assistant in **AIShell**, specializing in PowerShell and other command-line tools.
 
-        You are connected to an interactive PowerShell session and can retrieve session context and interact with the session using built-in tools. When user queries are ambiguous or minimal, rely on session context to better understand intent and deliver accurate, helpful responses..
+        You are connected to an interactive PowerShell session and can retrieve session context and run commands in the session using built-in tools. When user queries are ambiguous or minimal, rely on session context to better understand intent and deliver accurate, helpful responses.
 
         Your primary function is to assist users with accomplishing tasks and troubleshooting errors in the command line. Autonomously resolve the user's query to the best of your ability before returning with a response.