refactor: rename prompt from get_instances to get_servers

Align naming with compute_tools convention (server over instance)
as suggested in code review.

Author: paikend

src/openstack_mcp_server/prompts/__init__.py

@@ -7,14 +7,14 @@ def register_prompt(mcp: FastMCP):
     """
 
     @mcp.prompt()
-    def get_instances_by_security_group(security_group_name: str) -> str:
+    def get_servers_by_security_group(security_group_name: str) -> str:
         """
-        Get instances associated with a specific security group.
+        Get servers associated with a specific security group.
 
-        :param security_group_name: The name of the security group to filter instances by.
+        :param security_group_name: The name of the security group to filter servers by.
         """
         return (
-            f"Find all compute instances that have the security group "
+            f"Find all compute servers that have the security group "
             f"'{security_group_name}' attached.\n\n"
             f"Steps:\n"
             f"1. Call get_servers to list all servers.\n"

tests/prompts/test_prompts.py

@@ -1,7 +1,7 @@
 from openstack_mcp_server.prompts import register_prompt
 
 
-def test_get_instances_by_security_group_prompt_registered():
+def test_get_servers_by_security_group_prompt_registered():
     """Test that the prompt is registered with the MCP instance."""
     from unittest.mock import MagicMock
 
@@ -10,17 +10,17 @@ def test_get_instances_by_security_group_prompt_registered():
     mcp.prompt.assert_called()
 
 
-def test_get_instances_by_security_group_prompt_content():
+def test_get_servers_by_security_group_prompt_content():
     """Test that the prompt returns expected content."""
     from fastmcp import FastMCP
 
     mcp = FastMCP("test")
     register_prompt(mcp)
 
     prompts = mcp._prompt_manager._prompts
-    assert "get_instances_by_security_group" in prompts
+    assert "get_servers_by_security_group" in prompts
 
-    prompt_obj = prompts["get_instances_by_security_group"]
+    prompt_obj = prompts["get_servers_by_security_group"]
     assert prompt_obj.fn is not None
 
     result = prompt_obj.fn(security_group_name="my-sg")