fix(pos): include BackgroundShopifyGlobal in targets.json reverse mapping

BackgroundShopifyGlobal (addEventListener/removeEventListener on the shopify
global) was not being picked up by build-docs-targets-json.mjs. The script
discovers APIs by parsing type signatures and recursively resolving nested
*Api names via getNestedApis(), but BackgroundShopifyGlobal is a global
interface that doesn't match the (\w+Api) extraction pattern.

Fix: reference BackgroundShopifyGlobal from DataTargetApi's type intersection
(it is the shopify global for data targets), add it to the build script's
apiFilePaths map, and widen the getNestedApis extraction regex to also match
*Global types. Now getNestedApis('DataTargetApi') naturally discovers
BackgroundShopifyGlobal, which flows into the reverse mapping as
BackgroundShopifyGlobal -> [pos.app.ready.data].

Regenerated 2026-07-rc docs data.

Author: henryStelle

packages/ui-extensions/docs/surfaces/point-of-sale/build-docs-targets-json.mjs

@@ -281,6 +281,7 @@ function getNestedApis(apiName) {
     CashDrawerApi: ['./api/cash-drawer-api/cash-drawer-api'],
     PinPadApi: ['./api/pin-pad-api'],
     DataTargetApi: ['./api/data-target-api/data-target-api'],
+    BackgroundShopifyGlobal: ['./globals'],
   };
 
   const relativePaths = apiFilePaths[apiName];
@@ -354,8 +355,9 @@ function getNestedApis(apiName) {
     const typeDef = content.substring(startPos, endPos);
 
     // Extract all API names from the type definition
+    // Match both *Api types (e.g. SessionApi) and *Global types (e.g. BackgroundShopifyGlobal)
     const nestedApis = [];
-    const apiMatches = typeDef.matchAll(/(\w+Api)\b/g);
+    const apiMatches = typeDef.matchAll(/(\w+Api|\w+Global)\b/g);
 
     for (const apiMatch of apiMatches) {
       const nestedApiName = apiMatch[1];