infra: add main Terraform configuration and remove IAM JSON files

infra/terraform/main.tf

@@ -0,0 +1,22 @@
+terraform {
+  required_version = ">= 1.10.0"
+
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 5.0"
+    }
+  }
+
+  backend "s3" {
+    bucket       = "scalable-task-platform-tfstate"
+    key          = "main/terraform.tfstate"
+    region       = "us-east-1"
+    use_lockfile = true
+    encrypt      = true
+  }
+}
+
+provider "aws" {
+  region = var.aws_region
+}

infra/terraform/variables.tf

@@ -0,0 +1,39 @@
+variable "aws_region" {
+  description = "AWS region for all resources"
+  type        = string
+}
+
+variable "aws_account_id" {
+  description = "AWS account ID — set in terraform.tfvars, never hardcoded"
+  type        = string
+}
+
+variable "project_name" {
+  description = "Project name used for naming and tagging all resources"
+  type        = string
+  default     = "scalable-task-platform"
+}
+
+variable "environment" {
+  description = "Deployment environment"
+  type        = string
+  default     = "production"
+}
+
+variable "vpc_cidr" {
+  description = "CIDR block for the VPC"
+  type        = string
+  default     = "10.0.0.0/16"
+}
+
+variable "public_subnet_cidr" {
+  description = "CIDR block for the public subnet"
+  type        = string
+  default     = "10.0.1.0/24"
+}
+
+variable "private_subnet_cidr" {
+  description = "CIDR block for the private subnet"
+  type        = string
+  default     = "10.0.2.0/24"
+}