docs: add EC2 deployment playbooks (Windows + macOS) and link from README

- EC2-deployment.md: Windows/PowerShell playbook for Ubuntu 24.04 LTS
- EC2-deployment-macOS.md: macOS/Terminal playbook mirroring the same steps
- Both cover: Security Group setup, .pem permissions, venv, .env upload,
  manual smoke tests, systemd units (backend + frontend), Nginx reverse
  proxy with WebSocket headers, troubleshooting table, redeploy workflow,
  and optional HTTPS via Let's Encrypt
- README: new "Production Deployment" section linking both guides;
  fix stray ```clear typo
- .env.example: surface LangSmith variables (still optional, just visible)

Author: prashant9501

.env.example

@@ -1,5 +1,5 @@
 OPENAI_API_KEY=your_openai_api_key_here
 # Optional: enable LangSmith observability
-# LANGSMITH_API_KEY=your_langsmith_api_key_here
-# LANGSMITH_TRACING=true
-# LANGSMITH_PROJECT=securelife-mcp-chainlit
+LANGSMITH_API_KEY=your_langsmith_api_key_here
+LANGSMITH_TRACING=true
+LANGSMITH_PROJECT=securelife-mcp-chainlit-ec2