Fix pagination in mock drivers to use offset instead of skip

Co-authored-by: xuyushun441-sys <255036401+xuyushun441-sys@users.noreply.github.com>

Author: Copilot

packages/runtime/server/test/graphql.test.ts

@@ -43,10 +43,10 @@ class MockDriver implements Driver {
     async find(objectName: string, query: any) {
         let items = this.data[objectName] || [];
 
-        // Apply skip and limit if provided
+        // Apply offset and limit if provided (QueryAST uses 'offset', not 'skip')
         if (query) {
-            if (query.skip) {
-                items = items.slice(query.skip);
+            if (query.offset) {
+                items = items.slice(query.offset);
             }
             if (query.limit) {
                 items = items.slice(0, query.limit);

packages/runtime/server/test/rest-advanced.test.ts

@@ -41,9 +41,9 @@ class MockDriver implements Driver {
             }
         }
 
-        // Apply skip and top/limit (QueryAST uses 'top' for limit)
-        if (query?.skip) {
-            items = items.slice(query.skip);
+        // Apply offset and limit (QueryAST uses 'offset' for skip)
+        if (query?.offset) {
+            items = items.slice(query.offset);
         }
         if (query?.top || query?.limit) {
             items = items.slice(0, query.top || query.limit);
@@ -87,8 +87,9 @@ class MockDriver implements Driver {
     }
 
     async count(objectName: string, query: any) {
-        // Count should not apply skip/limit, only filters
+        // Count should not apply offset/limit, only filters
         const countQuery = { ...query };
+        delete countQuery.offset;
         delete countQuery.skip;
         delete countQuery.top;
         delete countQuery.limit;