Add TweetClaw as a real scan example

[kriptoburak]

Summary

• Add TweetClaw as a concrete networked OpenClaw skill example in the normal ClawGuard workflow.
• Point users at TweetClaw's packaged skills/tweetclaw directory so they can scan the local SKILL.md before installing or configuring the plugin.
• Keep the caveat explicit: the scan is pre-install review evidence, not a safety certificate.

Checks

• Searched open and closed issues, PRs, and repo content for existing TweetClaw or Xquik mentions before opening this PR.
• Checked the target repo, TweetClaw repo, and TweetClaw skills/tweetclaw URL.
• Ran pnpm install --frozen-lockfile --ignore-scripts.
• Ran pnpm format:check.
• Ran pnpm lint.
• Ran pnpm typecheck.
• Ran pnpm build.
• Ran pnpm test.