fix(grid): reset infinite scroll state on database sort

Closes #5172

apps/desktop/src/components/grid/DataGrid.vue

@@ -4379,8 +4379,12 @@ function setDetailNull() {
 
 function applyColumnSort(column: string, columnIndex: number, direction: "asc" | "desc" | null, mode: DataGridSortMode = "database") {
   if (getIsResizing()) return;
-  currentPage.value = 1;
-  resetGridVerticalScroll(true);
+  if (mode === "database" && infiniteScrollEnabled.value) {
+    resetInfiniteScrollState();
+  } else {
+    currentPage.value = 1;
+    resetGridVerticalScroll(true);
+  }
   if (direction) {
     setSort(column, columnIndex, direction, mode);
     if (mode === "database") {

apps/desktop/src/components/grid/__tests__/DataGridInfiniteScrollSort.spec.ts

@@ -0,0 +1,35 @@
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+const dataGridSource = readFileSync(new URL("../DataGrid.vue", import.meta.url), "utf8");
+
+function functionSource(name: string, nextName: string): string {
+  const start = dataGridSource.indexOf(`function ${name}`);
+  const relativeEnd = dataGridSource.slice(start).search(new RegExp(`\\n(?:async\\s+)?function\\s+${nextName}\\b`));
+  expect(start).toBeGreaterThanOrEqual(0);
+  expect(relativeEnd).toBeGreaterThan(0);
+  const end = start + relativeEnd;
+  return dataGridSource.slice(start, end);
+}
+
+describe("DataGrid infinite-scroll sorting", () => {
+  it("clears completed and pending infinite-scroll state before database sorting", () => {
+    const sortSource = functionSource("applyColumnSort", "selectHeaderSort");
+    const resetSource = functionSource("resetInfiniteScrollState", "onToolbarRefresh");
+
+    expect(sortSource).toContain('if (mode === "database" && infiniteScrollEnabled.value) {\n    resetInfiniteScrollState();');
+    expect(resetSource).toContain("lastInfiniteScrollPage = 0;");
+    expect(resetSource).toContain("infiniteScrollAllLoaded = false;");
+    expect(resetSource).toContain("infiniteScrollRequestedOffset = undefined;");
+    expect(resetSource).toContain("infiniteScrollRequestedLimit = undefined;");
+    expect(resetSource).toContain("isInfiniteScrollPaginating.value = false;");
+    expect(resetSource).toContain("infiniteScrollLoading.value = false;");
+  });
+
+  it("preserves the existing lightweight reset for local sorting", () => {
+    const sortSource = functionSource("applyColumnSort", "selectHeaderSort");
+
+    expect(sortSource).toContain("} else {\n    currentPage.value = 1;\n    resetGridVerticalScroll(true);\n  }");
+    expect(sortSource.match(/emit\("sort"/g)).toHaveLength(1);
+  });
+});