Add optional Hermes Tweet read backend

[kriptoburak]

Summary

• Add AUTH_METHOD=hermes_tweet for public read tools through a Hermes Tweet/Xquik-compatible backend.
• Route tweet search, tweet lookup, user tweets, profiles, followers, and following reads without requiring Twitter cookies or account credentials.
• Keep write, follow, and Grok tools on the existing auth methods with a clear read-only error, plus docs, Smithery config, env examples, and Jest coverage.

Validation

• npm ci
• npm run lint
• npm test
• npm run build
• git diff --check
• curl -LIs --max-time 20 -o /dev/null -w '%{http_code} %{url_effective}' https://xquik.com returned 200 https://xquik.com/en

Duplicate PR and issue searches for Hermes Tweet/Xquik routes were clean before opening this PR. The fork is under the personal kriptoburak account and points back to ryanmac/agent-twitter-client-mcp.