fix: offset falsy check in pipeline assembly — offset:0 skipped LimitOperator

Four sites in local-executor.ts and operators.ts (assemblePipeline) used
`query.offset ||` which is falsy when offset is 0. Changed to
`query.offset !== undefined ||` for correctness.

Author: teamchong

src/local-executor.ts

@@ -610,7 +610,7 @@ export class LocalExecutor implements QueryExecutor {
         pipeline = new TopKOperator(pipeline, query.sortColumn, query.sortDirection === "desc", query.limit, query.offset ?? 0);
       } else if (query.sortColumn) {
         pipeline = new InMemorySortOperator(pipeline, query.sortColumn, query.sortDirection === "desc", query.offset ?? 0);
-      } else if (query.offset || query.limit !== undefined) {
+      } else if (query.offset !== undefined || query.limit !== undefined) {
         pipeline = new LimitOperator(pipeline, query.limit ?? Infinity, query.offset ?? 0);
       }
     } else if (query.sortColumn) {
@@ -619,7 +619,7 @@ export class LocalExecutor implements QueryExecutor {
       } else {
         pipeline = new ExternalSortOperator(pipeline, query.sortColumn, query.sortDirection === "desc", query.offset ?? 0, pipeOpts?.memoryBudgetBytes ?? DEFAULT_MEMORY_BUDGET);
       }
-    } else if (query.offset || query.limit !== undefined) {
+    } else if (query.offset !== undefined || query.limit !== undefined) {
       pipeline = new LimitOperator(pipeline, query.limit ?? Infinity, query.offset ?? 0);
     }
 

src/operators.ts

@@ -3066,7 +3066,7 @@ function assemblePipeline(
         pipeline, query.sortColumn, query.sortDirection === "desc",
         query.offset ?? 0,
       );
-    } else if (query.offset || query.limit !== undefined) {
+    } else if (query.offset !== undefined || query.limit !== undefined) {
       pipeline = new LimitOperator(pipeline, query.limit ?? Infinity, query.offset ?? 0);
     }
   } else if (query.sortColumn) {
@@ -3081,7 +3081,7 @@ function assemblePipeline(
         query.offset ?? 0, memBudget, options?.spill,
       );
     }
-  } else if (query.offset || query.limit !== undefined) {
+  } else if (query.offset !== undefined || query.limit !== undefined) {
     pipeline = new LimitOperator(pipeline, query.limit ?? Infinity, query.offset ?? 0);
   }