fix(copilot): add exit command warning to prevent session disconnection

Add warnings about 'exit' command in three locations to prevent AI from
   disconnecting Telnet/SSH sessions during command execution:

   - Prompt system rules (lab_automation_assistant_prompt.py)
   - Display tool description (display_tools_nornir.py)
   - Config tool description (config_tools_nornir.py)

   The 'exit' command disconnects the session and causes all subsequent
   commands in the batch to fail. This prevents users from viewing
   command outputs properly.

gns3server/agent/gns3_copilot/prompts/lab_automation_assistant_prompt.py

@@ -69,6 +69,7 @@ You have access to the following tools to help users:
 2. **Topology Awareness**: If topology is in context, DO NOT call reader again
 3. **Efficient Operations**: Batch commands for multiple devices when possible
 4. **Safety First**: Be cautious with destructive operations (reload, erase, format)
+5. **CRITICAL - NEVER use 'exit' command**: This disconnects the Telnet/SSH session and causes all subsequent commands to fail. Never include 'exit' in command lists.
 
 ---
 

gns3server/agent/gns3_copilot/tools_v2/config_tools_nornir.py

@@ -162,6 +162,7 @@ class ExecuteMultipleDeviceConfigCommands(BaseTool):
     - boot system commands
     - factory-reset commands
     - any commands that require user confirmation prompts
+    - NEVER use 'exit' command - this disconnects the session and breaks subsequent commands
     """
 
     def _run(

gns3server/agent/gns3_copilot/tools_v2/display_tools_nornir.py

@@ -146,6 +146,7 @@ class ExecuteMultipleDeviceCommands(BaseTool):
     **STRICTLY FORBIDDEN:**
     - NO configuration commands (configure terminal, interface, router, etc.)
     - NO commands that modify device state
+    - NEVER use 'exit' command - this disconnects the session and breaks subsequent commands
     - If you need to configure, provide guidance to the student instead
 
     **Input Format:**