test: use mocha CLI directly for node tests

I've opted to leave the mocha grunt task alons for now since it's used
for test:webserver and has the configuration to emit JUnit XML in case
we want to set up test-observability in future.

.mocharc.js

@@ -0,0 +1,3 @@
+module.exports = {
+  require: ['test/support/modules_helper.js', 'test/support/test_helper.js']
+}

CONTRIBUTING.md

@@ -45,17 +45,17 @@ Run the Mocha test suite
 
     npm run test:node
 
-Or run just one test file
+You can pass any Mocha CLI arguments and flags to the test:node script after the `--` separator, for example running one test file:
 
-    npm run test:node -- --file=test/realtime/auth.test.js
+    npm run test:node -- test/realtime/auth.test.js
 
 Or run just one test
 
-    npm run test:node -- --file=test/rest/status.test.js --grep=test_name_here 
+    npm run test:node -- --grep=test_name_here
 
 Or run test skipping the build
 
-    npm run test:node:skip-build -- --file=test/rest/status.test.js --grep=test_name_here 
+    npm run test:node:skip-build -- test/rest/status.test.js --grep=test_name_here
 
 ### Debugging the mocha tests locally with a debugger
 

package.json

@@ -130,9 +130,9 @@
   "scripts": {
     "start:react": "npx vite serve",
     "grunt": "grunt",
-    "test": "grunt test",
-    "test:node": "grunt test:node",
-    "test:node:skip-build": "grunt mocha",
+    "test": "npm run test:node",
+    "test:node": "npm run build:node && mocha",
+    "test:node:skip-build": "mocha",
     "test:webserver": "grunt test:webserver",
     "test:playwright": "node test/support/runPlaywrightTests.js",
     "test:react": "vitest run",