feat: switch site contact email to ceo@, add WhatsApp hotline

Replaces hello@auraajenticai.cloud with ceo@auraajenticai.cloud across every
display/mailto surface (nav CTA, contact page, direct-contact card, JSON-LD),
and adds +8801911877091 as a real WhatsApp contact channel (click-to-chat
link on the Contact page and the home page's Direct card, plus telephone in
the Organization schema). The contact form itself is unaffected — it already
posts to a separate address via formsubmit.co, not through this email.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

index.html

@@ -32,7 +32,8 @@
       "logo": "https://auraajenticai.cloud/logo.png",
       "image": "https://auraajenticai.cloud/logo.png",
       "description": "Aura Agentic AI builds custom AI agents, automation pipelines, Web3 infrastructure, MT5 trading systems, data pipelines, and enterprise web apps — based in Dhaka, serving clients worldwide.",
-      "email": "hello@auraajenticai.cloud",
+      "email": "ceo@auraajenticai.cloud",
+      "telephone": "+8801911877091",
       "foundingDate": "2017",
       "areaServed": "Worldwide",
       "address": {