fix(filesystem): fix move_file outputSchema to return array

The move_file tool was returning raw string instead of array of content objects,
causing MCP protocol -32602 validation errors.

Closes #3093

Author: huangzhimou

.changeset/fix-move-file-output-schema.md

@@ -0,0 +1,5 @@
+---
+"@modelcontextprotocol/server-filesystem": patch
+---
+
+Fix move_file outputSchema to return array of content objects instead of string. Closes #3093

src/filesystem/index.ts

@@ -607,7 +607,7 @@ server.registerTool(
       source: z.string(),
       destination: z.string()
     },
-    outputSchema: { content: z.string() },
+    outputSchema: { content: z.array(z.object({ type: z.enum(["text"]), text: z.string() })) },
     annotations: { readOnlyHint: false, idempotentHint: false, destructiveHint: true }
   },
   async (args: z.infer<typeof MoveFileArgsSchema>) => {