chore(infra): enable S3 backend after bootstrap

State bucket and DynamoDB lock table have been provisioned.
Switches from local state to remote S3 backend.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Mohitsharma44

infra/providers.tf

@@ -8,18 +8,14 @@ terraform {
     }
   }
 
-  # S3 backend will be configured after bootstrap (state.tf resources created first)
-  # Uncomment after running: terraform apply -target=aws_s3_bucket.state -target=aws_dynamodb_table.state_lock
-  # Then run: terraform init -migrate-state
-  #
-  # backend "s3" {
-  #   bucket         = "cuspuo-terraform-state"
-  #   key            = "cuspuo-site/terraform.tfstate"
-  #   region         = "us-east-1"
-  #   dynamodb_table = "cuspuo-terraform-lock"
-  #   encrypt        = true
-  #   profile        = "muon"
-  # }
+  backend "s3" {
+    bucket         = "cuspuo-terraform-state"
+    key            = "cuspuo-site/terraform.tfstate"
+    region         = "us-east-1"
+    dynamodb_table = "cuspuo-terraform-lock"
+    encrypt        = true
+    profile        = "muon"
+  }
 }
 
 provider "aws" {