Add default values to variables and remove terraform.tfvars

Changes:
- Added default values to datacenter, cluster_name, and environment variables
- Default values match production environment (WBYC-DC01, wbyc-cluster01, prd)
- Updated variable descriptions to note CI/CD secret usage
- terraform.tfvars has been cleaned locally (already in .gitignore)

Benefits:
- No terraform.tfvars file needed for standard deployment
- CI/CD secrets can override defaults when needed
- Cleaner repository without sensitive data
- Variables have sensible defaults for this environment

variables.tf

@@ -1,19 +1,21 @@
 
 variable "datacenter" {
-  description = "vSphere data center"
+  description = "vSphere data center (provided via CI/CD secrets as TF_VAR_datacenter)"
   type        = string
+  default     = "WBYC-DC01"
 }
 
 variable "cluster_name" {
-  description = "vSphere Cluster Name"
+  description = "vSphere Cluster Name (provided via CI/CD secrets as TF_VAR_cluster_name)"
   type        = string
+  default     = "wbyc-cluster01"
 }
 
-
 # Environment
 variable "environment" {
-  description = "Environment name can be: dev, tst, acc, uat, prod, shared or tools"
+  description = "Environment name can be: dev, tst, acc, uat, prod, shared or tools (provided via CI/CD secrets as TF_VAR_environment)"
   type        = string
+  default     = "prd"
 }
 
 # Resource Groups