fix: country list fixes for shipping-zones-list component (#153)

- Remove asterisks from United Kingdom and United States
- Move China to alphabetical position
- Remove "Flat rate" option
- Alphabetize country list

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/components/shipping-zones-list.js

@@ -20,7 +20,6 @@ window.app.component('shipping-zones-list', {
       currencies: [],
       shippingZoneOptions: [
         'Free (digital)',
-        'Flat rate',
         'Worldwide',
         'Europe',
         'Australia',
@@ -28,6 +27,7 @@ window.app.component('shipping-zones-list', {
         'Belgium',
         'Brazil',
         'Canada',
+        'China',
         'Denmark',
         'Finland',
         'France',
@@ -35,8 +35,8 @@ window.app.component('shipping-zones-list', {
         'Greece',
         'Hong Kong',
         'Hungary',
-        'Ireland',
         'Indonesia',
+        'Ireland',
         'Israel',
         'Italy',
         'Japan',
@@ -60,10 +60,9 @@ window.app.component('shipping-zones-list', {
         'Thailand',
         'Turkey',
         'Ukraine',
-        'United Kingdom**',
-        'United States***',
-        'Vietnam',
-        'China'
+        'United Kingdom',
+        'United States',
+        'Vietnam'
       ],
       zonesTable: {
         columns: [