docs(wporg): optimize the directory listing for search and conversion

[cport1]

Readme-only. Optimizes the wp.org listing ahead of the adoption push:

• Keyworded display name (the heaviest wp.org search signal): WebDecoy Bot Detection - Block AI Crawlers, Spam Bots & Card Testing
• Tags 5 → 12 (the allowed max): adds honeypot, ai bots, captcha, bot blocker, brute force, fraud prevention, anti-spam
• Short description rewritten around searched-for jobs: AI crawlers, CAPTCHA-free, card testing
• Deception finally on the listing: new "zero-false-positive layer" section + Deception & Traps block in Free Features. Tripwires/honeytokens/canary credentials are the differentiator and were nearly absent
• Two long-tail FAQs: "Can WebDecoy replace my CAPTCHA plugin?" and "How is it different from a firewall or malware scanner?"
• Screenshots section fixed: 7 captions for the 7 images that exist (was 8)
• Em-dash sweep of the entire readme per the copy directive

After merge: sync readme.txt to SVN trunk/ + tags/2.4.0/ (the directory serves the stable tag's readme). No code, no version bump, no release needed.