docs: add TweetClaw X/Twitter research handoff

[kriptoburak]

Summary

• add a TweetClaw handoff for OpenClaw workflows that need X/Twitter research before scheduling
• keep SocialClaw scoped to validation, scheduling, publishing, inspection, and analytics
• sync the OpenClaw reference workflow into the packaged skill copy

Checks

• git diff --check
• added-line dash and sensitive-string scans
• changed-file link sweep: 27 unique external URLs, 13 local links, 0 unexpected failures
• npm test
• npm run pack:check