5d: the review's image swap, teardown trap and fixture-name assertions

docker-runner.sh

@@ -1,20 +1,21 @@
 bun_image=oven/bun:1.4.0-alpine
 deno_image=denoland/deno:2.9.6
-firefox_image=instrumentisto/geckodriver:149.0.2
+firefox_image=selenium/standalone-firefox:153.0.4
 floor_image=node:18.20.8-alpine3.21
 node_image=node:24.19.0-alpine3.24
 
 in_image() {
   local image=$1 entrypoint=$2
   shift 2
-  docker run --rm -u "$(id -u):$(id -g)" -e HOME=/tmp ${network:+--network "$network"} -v "$PWD:/app" -w /app --entrypoint "$entrypoint" "$image" "$@"
+  docker run --rm -u "$(id -u):$(id -g)" -e HOME=/tmp ${in_image_network:+--network "$in_image_network"} -v "$PWD:/app" -w /app --entrypoint "$entrypoint" "$image" "$@"
 }
 
 with_firefox() {
-  local container network status=0
+  local container in_image_network status=0
   container=$(docker run -d --rm "$firefox_image")
-  network="container:$container"
+  # The id is baked in: the trap fires after this function's locals are gone.
+  trap "docker rm -f $container >/dev/null 2>&1" EXIT INT TERM
+  in_image_network="container:$container"
   "$@" || status=$?
-  docker rm -f "$container" >/dev/null
   return $status
 }