Release 1.2.2: fix load-balancing crash (wrong lua-resty-balancer module)

Every request to a host with additional load-balancing targets 500'd:
targetinfo.lua required 'resty.balancer.round_robin', which does not
exist in the lua-resty-balancer rock actually installed by the
Dockerfile/install.sh. That rock provides resty.roundrobin instead,
with a different constructor (roundrobin:new(nodes), not
:new() + :reinit(nodes)).

Verified end-to-end in a rebuilt image: requests to a load-balanced
host now return 200 and alternate across both backend targets, with
no Lua errors in the OpenResty log.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

nodejs/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "proxy-api",
-  "version": "1.2.1",
+  "version": "1.2.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "proxy-api",
-      "version": "1.2.1",
+      "version": "1.2.2",
       "license": "MIT",
       "dependencies": {
         "@fortawesome/fontawesome-free": "^7.3.0",