add tester ui, and restructure folders

ctrl/invoke.sh

@@ -1,3 +1,12 @@
 #!/usr/bin/env bash
+# Invoke a function from functions/ directly via `python invoke.py`.
+# Usage:
+#   ctrl/invoke.sh                                  # default: first function found
+#   ctrl/invoke.sh lambda_function                  # specific function
+#   ctrl/invoke.sh lambda_function '{"key":"val"}'  # with event payload
+#
+# For the same invocation through the FastAPI tester (with cold/warm + memory
+# metrics) use the Lambda Tester tab at http://eth.local.ar or POST to
+# http://eth.local.ar/runner/invoke/<name>.
 set -euo pipefail
 kubectl --context kind-eth -n eth exec -i deploy/lambda -- python invoke.py "$@"