Refresh TweetClaw MPP description

[kriptoburak]

Summary

• Refresh the existing TweetClaw entry so it no longer claims 120 endpoints.
• Keep README.md and registry.json aligned with current MPP guidance.
• Clarify that MPP covers 31 read-only X API endpoints while account-backed flows handle visible X/Twitter actions and monitoring.

Checks

• node -e "JSON.parse(require('fs').readFileSync('registry.json','utf8')); console.log('registry json ok')"
• git diff --check
• curl -L -s -o /dev/null -w '%{http_code} %{url_effective}\n' https://github.com/Xquik-dev/tweetclaw