docs: add TweetClaw source memory workflow

[kriptoburak]

Summary

• document a Cortex and TweetClaw workflow for saving concise public X/Twitter source memories
• install TweetClaw from npm with openclaw plugins install @xquik/tweetclaw, with ClawHub as a browsing page while its listing lags behind npm
• keep raw timelines, private account material, DMs, cookies, API keys, and exported files out of saved memories
• fix the Cortex Memory install command from openclaw plugin install to openclaw plugins install
• remove an existing broken public link to the private Cortex repo from the README intro

Duplicate Checks

• searched open and closed PRs in Ubundi/openclaw-cortex for TweetClaw, tweetclaw, @xquik/tweetclaw, the TweetClaw GitHub URL, the npm package URL, the ClawHub listing, and spelling variants
• searched issues for the same terms
• no existing TweetClaw or Xquik thread was found beyond this PR

Current TweetClaw Data

• npm latest: @xquik/tweetclaw@1.6.31
• openclaw.install.defaultChoice: npm
• openclaw.install.npmSpec: @xquik/tweetclaw@1.6.31
• canonical GitHub: https://github.com/Xquik-dev/tweetclaw
• canonical npm package: https://www.npmjs.com/package/@xquik/tweetclaw
• ClawHub browsing page: https://clawhub.ai/plugins/@xquik/tweetclaw

Validation

• git diff --check
• stale guard for old TweetClaw versions, bad ClawHub routes, singular OpenClaw install commands, and conflict markers
• changed-line credential scan for token and secret patterns
• link checks for TweetClaw GitHub, ClawHub, and the npm registry endpoint
• npm ci --ignore-scripts
• npx tsc --noEmit
• npm test
• npm run verify-release
• npm run build

Notes: the npm web page returned bot protection to curl, so the npm registry endpoint was used for package verification. npm ci --ignore-scripts reported existing audit findings without dependency changes.