Update to math-proof

{
  "official": [
    {
      "name": "math-proof",
      "author": {
        "name": "Anthropic",
        "email": "support@anthropic.com"
      },
      "source": "./plugins/math-proof",
      "category": "math",
      "homepage": "https://github.com/anthropics/claude-plugins-official/tree/main/plugins/math-proof",
      "description": "Two skills for hard mathematics problems, each ending in a self-contained proof.md: /math-proof:solo has the session work the problem itself in stages with a notes file; /math-proof:siege works on it for hours in rounds of judge and worker sub-agents and says plainly what is and is not proved."
    }
  ]
}