feat: add twitter manual helper commands

[777genius]

Summary:

• Add a read-only twitter_browser.py search command for collecting visible X search results
• Add reply-plain to reply without campaign suffix injection
• Document both commands in the script usage block

Tests:

• python3 -m py_compile scripts/twitter_browser.py
• git diff --check
• staged diff reviewed for local config, accounts, tokens, cookies, and product-specific data