docs: add TweetClaw watchdog example

[kriptoburak]

Summary

• add TweetClaw as a concrete long-running OpenClaw plugin workflow for openclaw-cli watch
• link the canonical TweetClaw GitHub repo, npm package, and ClawHub listing
• keep OpenClaw CLI framed as the gateway watchdog while showing why daemon monitoring helps plugin workloads

Validation

• git diff --check
• README content check for TweetClaw links and workflow wording
• added-line scan for dash and sensitive-placeholder patterns
• live link checks for target GitHub, target site, TweetClaw GitHub, and TweetClaw ClawHub
• npm metadata readback for openclaw-cli@0.7.2 and @xquik/tweetclaw@1.6.31

Note: npmjs.com package pages returned 403 to curl bot-protection checks, but npm registry metadata resolved successfully.