Remove em dashes from the MCP server.json description

Missed this one earlier — it's the text that will show up in the official
MCP registry listing once posecode-mcp is submitted.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B7RkyiTt9soiYdw5vt6BEP

Author: claude

packages/posecode-mcp/server.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
   "name": "io.github.posecode-dev/posecode-mcp",
-  "description": "Author, ROM-validate, and render 3D human movement (.posecode) — exercises, physiotherapy, posture — with a shareable playground link.",
+  "description": "Author, ROM-validate, and render 3D human movement (.posecode): exercises, physiotherapy, posture, with a shareable playground link.",
   "repository": {
     "url": "https://github.com/posecode-dev/posecode",
     "source": "github"