added infra setup with terraform

infra/terraform.tfvars.example

@@ -0,0 +1,10 @@
+# Copy to terraform.tfvars and fill in your values
+vpc_id     = "vpc-0abc123def456"
+subnet_ids = ["subnet-0abc123", "subnet-0def456"]  # 2+ subnets in different AZs
+db_password = "change-me-to-something-secure"
+ssh_cidr    = "203.0.113.50/32"  # Your home IP
+
+# Optional overrides:
+# region           = "us-east-1"
+# ec2_instance_type = "c5.xlarge"
+# scanning          = true