Add dry-run review mode

[kriptoburak]

Summary

• Add a global --dry-run option for tweet and reply.
• Print the exact JSON write payload without resolving cookies, reading media files, or posting.
• Document the agent review flow and the optional OpenClaw/TweetClaw handoff for reviewed research and approval-gated X/Twitter workflows.

Validation

• pnpm test
• pnpm run build
• pnpm exec biome check README.md src/index.ts tests/cli.test.ts
• npx --yes markdown-link-check README.md --quiet
• git diff --check

Note: full pnpm run lint still reports pre-existing issues in unmodified files: formatting in src/lib/sweetistics-client.ts, tests/cookies.test.ts, tests/twitter-client.test.ts, plus an existing noAssignInExpressions finding in tests/twitter-client.test.ts.