refactor: rename StrandsAgent to FASTAgent in CDK and Terraform

Rename the default agent name from StrandsAgent to FASTAgent since the
template is framework-agnostic and supports multiple patterns.

Updated in:
- infra-cdk/lib/backend-stack.ts (CfnParameter default)
- infra-terraform/modules/backend/locals.tf
- infra-terraform/README.md

Note: the CDK change is slightly out of scope for this Terraform-focused
PR but included here to keep the two infra tools in sync.

Author: kaleko

infra-cdk/lib/backend-stack.ts

@@ -102,7 +102,7 @@ export class BackendStack extends cdk.NestedStack {
     // Parameters
     this.agentName = new cdk.CfnParameter(this, "AgentName", {
       type: "String",
-      default: "StrandsAgent",
+      default: "FASTAgent",
       description: "Name for the agent runtime",
     })
 

infra-terraform/README.md

@@ -66,7 +66,7 @@ Terraform uses flat variables with a `backend_` prefix to mirror the CDK's neste
 | `backend.vpc.subnet_ids` | `backend_vpc_subnet_ids` |
 | `backend.vpc.security_group_ids` | `backend_vpc_security_group_ids` |
 
-Values that are hardcoded in CDK (not in `config.yaml`) are defined as module-internal locals in Terraform: agent name (`StrandsAgent`), memory event expiry (30 days), callback URLs, and password minimum length.
+Values that are hardcoded in CDK (not in `config.yaml`) are defined as module-internal locals in Terraform: agent name (`FASTAgent`), memory event expiry (30 days), callback URLs, and password minimum length.
 
 ## Module Structure
 

infra-terraform/modules/backend/locals.tf

@@ -22,8 +22,8 @@ locals {
   # Stack name for resource naming (underscores for some AWS resources)
   stack_name_underscore = replace(var.stack_name_base, "-", "_")
 
-  # Agent name (matches CDK CfnParameter default in backend-stack.ts)
-  agent_name = "StrandsAgent"
+  # Agent name used in runtime naming
+  agent_name = "FASTAgent"
 
   # Runtime name (underscores required by AgentCore)
   runtime_name = "${local.stack_name_underscore}_${local.agent_name}"