fix(scripts): fail update-export-versions if snapshot update fails

The script was silently swallowing errors when snapshot updates failed,
causing versions.ts to be committed without matching snapshots. This led
to CI failures in the coverage workflow.

Changes:
- Exit with code 1 if snapshot update fails
- Only update snapshots when versions actually changed (avoids requiring
  build for check-only workflows)

Author: pasevin

scripts/update-export-versions.cjs

@@ -77,13 +77,15 @@ const updateVersionsFile = () => {
   if (versionsUpdated) {
     fs.writeFileSync(versionsFilePath, fileContent, 'utf8');
     console.log('\n🎉 Successfully synchronized versions.ts!');
+
+    // Only update snapshots when versions actually changed
+    // This requires packages to be built, so we only do it when necessary
+    console.log('\n📸 Updating snapshots to match new versions...');
+    updateSnapshots();
   } else {
     console.log('\n✅ All versions in versions.ts are already up to date.');
+    console.log('   Skipping snapshot update (no version changes detected).');
   }
-
-  // Always update snapshots to ensure they match current versions
-  console.log('\n📸 Ensuring snapshots match current versions...');
-  updateSnapshots();
 };
 
 const updateSnapshots = () => {
@@ -99,9 +101,14 @@ const updateSnapshots = () => {
     console.log('✅ Snapshots updated successfully!');
   } catch (error) {
     console.error('❌ Failed to update snapshots:', error.message);
-    console.log(
-      '⚠️  Please run "pnpm --filter @openzeppelin/ui-builder-app test src/export/__tests__/ -- -u" manually'
+    console.error(
+      '⚠️  Snapshot update failed. This will cause CI failures if versions.ts is committed without matching snapshots.'
+    );
+    console.error(
+      '   To fix manually, run: pnpm --filter @openzeppelin/ui-builder-app test src/export/__tests__/ -- -u'
     );
+    // Exit with error code to prevent committing mismatched versions
+    process.exit(1);
   }
 };