chore: add Terraform files to gitignore and remove from tracking

Author: Augment Agent

.gitignore

@@ -37,4 +37,10 @@ config.testnet.yaml
 config.mainnet.yaml
 config.yaml
 
-gcp.json
+gcp.json
+
+# Terraform
+**/.terraform/
+**/.terraform.lock.hcl
+*.tfstate
+*.tfstate.backup