fix(examples): Ensure WordPress and frontend start concurrently

Updated example:start scripts in both toolbar demos to use concurrently
properly. WordPress and frontend now start together using concurrently,
with a 5 second delay on frontend to ensure WordPress completes startup.

Changes:
- Separated wp-env setup (npm install) into wp:ensure script
- Modified wp:start to only run wp-env start (no blocking npm install)
- Used concurrently to run both services in parallel
- Added sleep 5 before frontend start to allow wp-env initialization

Author: josephfusco

examples/next/toolbar-demo/package.json

@@ -6,9 +6,10 @@
   "scripts": {
     "example:dev": "npm --prefix ./example-app run dev",
     "example:build": "npm --prefix ./example-app run build",
-    "example:start": "node scripts/setup-env.js && concurrently \"npm run wp:start\" \"npm run example:dev\"",
+    "example:start": "node scripts/setup-env.js && npm run wp:ensure && concurrently \"npm run wp:start\" \"sleep 5 && npm run example:dev\"",
     "example:stop": "npm run wp:stop",
-    "wp:start": "npm install && wp-env start",
+    "wp:ensure": "npm install",
+    "wp:start": "wp-env start",
     "wp:stop": "wp-env stop",
     "wp:destroy": "wp-env destroy"
   },

examples/vanilla/toolbar-demo/package.json

@@ -5,11 +5,12 @@
   "scripts": {
     "example:build": "npm run example:dev:install && npm run wp:start && npm run example:start",
     "example:dev:install": "cd example-app && npm install && cd ..",
-    "example:start": "node scripts/setup-env.js && concurrently \"npm run wp:start\" \"npm run example:dev\"",
+    "example:start": "node scripts/setup-env.js && npm run wp:ensure && concurrently \"npm run wp:start\" \"sleep 5 && npm run example:dev\"",
     "example:stop": "npm run wp:stop",
     "example:prune": "wp-env destroy && npm run example:build && npm run example:start",
     "example:dev": "npm --prefix ./example-app run dev",
-    "wp:start": "npm install && wp-env start",
+    "wp:ensure": "npm install",
+    "wp:start": "wp-env start",
     "wp:stop": "wp-env stop",
     "wp:destroy": "wp-env destroy",
     "wp-env": "wp-env"