Add prefabCreationPrompt for prefab workflow

Added a new MCP server prompt prefabCreationPrompt defining the proper workflow for creating prefabs in Unity with optional MonoBehaviour scripts and serialized fields.

Author: CoderGamester

Server~/src/prompts/prefabCreationPrompt.ts

@@ -0,0 +1,56 @@
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import * as z from "zod";
+
+/**
+ * Registers the prefab creation prompt with the MCP server.
+ * This prompt defines the proper workflow for creating prefabs in Unity, optionally with MonoBehaviour scripts.
+ * 
+ * @param server The McpServer instance to register the prompt with.
+ */
+export function registerPrefabCreationPrompt(server: McpServer) {
+  server.prompt(
+    'prefab_creation_strategy',
+    'Defines the proper workflow for creating prefabs in Unity, optionally with MonoBehaviour scripts',
+    {
+      scriptName: z.string().optional().describe("The name of the MonoBehaviour script to create a prefab from (without .cs extension). Optional."),
+      prefabName: z.string().describe("The name for the new prefab (without .prefab extension)."),
+      fieldValues: z.string().optional().describe("Optional key-value pairs to set serialized field values on the component, as a JSON string."),
+    },
+    async ({ scriptName, prefabName, fieldValues }) => ({
+      messages: [
+        {
+          role: 'user', 
+          content: {
+            type: 'text',
+            text: `You are an expert AI assistant integrated with Unity via MCP.
+
+When creating prefabs in Unity, you have access to the following tools:
+- Tool "create_prefab" to create a prefab with optional MonoBehaviour script and serialized field values.
+
+Workflow:
+1. Determine an appropriate name for the new prefab.
+2. Optionally, identify the MonoBehaviour script name that should be used for the prefab.
+3. Optionally, identify any serialized field values that should be set on the component.
+4. Use the "create_prefab" tool with the prefab name, optional script name, and optional field values.
+5. Confirm success and report the path of the created prefab.
+
+Guidance:
+- The script must already be compiled in the Unity project if provided.
+- The prefab will be saved in the Assets/Prefabs/ directory.
+- If a prefab with the same name already exists, a unique name will be generated.
+- Field values should match the serialized fields in the MonoBehaviour script if provided.
+- Field values should be provided as a JSON string.
+- Always validate inputs and request clarification if needed.`
+          }
+        },
+        {
+          role: 'user',
+          content: {
+            type: 'text',
+            text: `Create a prefab named "${prefabName}"${scriptName ? ` from the script "${scriptName}"` : ''}${fieldValues ? ` with field values: ${fieldValues}` : ''}.`
+          }
+        }
+      ]
+    })
+  );
+}