fix(objects): pin object list vertical scrollbar to the viewport

When the object-browser columns exceeded the panel width, the vertical
scrollbar travelled with the content: the row scroller was stretched to
the content min-width inside the horizontally scrolling table container,
so its scrollbar sat at the far-right edge of the (off-screen) content
and users had to scroll all the way right to reach it (#8885).

The list scroller now stays viewport-width and owns the horizontal
scrolling itself (content min-width moves to the virtual-scroller item
wrapper), and the header becomes a clipped wrapper whose scrollLeft is
kept in sync with the scroller on scroll, resize, and re-attach.

apps/desktop/src/components/objects/__tests__/ObjectBrowser.verticalScrollbarViewport.spec.ts

@@ -0,0 +1,41 @@
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+const source = readFileSync(new URL("../ObjectBrowser.vue", import.meta.url), "utf8");
+
+// Regression test for #8885: when the object-browser columns are wider than the
+// panel, the vertical scrollbar must stay pinned to the visible right edge
+// instead of travelling with the content. The list scroller therefore owns the
+// horizontal scrolling (with the content width applied to its inner item
+// wrapper), while the header is clipped and aligned programmatically.
+describe("ObjectBrowser vertical scrollbar viewport lock", () => {
+  it("keeps the outer table container from scrolling horizontally", () => {
+    const tableMatch = /class="object-browser-table[^"]*"/.exec(source);
+    expect(tableMatch).not.toBeNull();
+    expect(tableMatch![0]).toContain("overflow-hidden");
+    expect(tableMatch![0]).not.toContain("overflow-x-auto");
+  });
+
+  it("moves the content min-width onto the scroller's inner wrapper", () => {
+    const scrollerMatch = /<RecycleScroller[^>]*listScrollerRef[^>]*>/.exec(source);
+    expect(scrollerMatch).not.toBeNull();
+    expect(scrollerMatch![0]).toContain("--dbx-object-grid-min-width");
+    expect(scrollerMatch![0]).not.toContain("minWidth:");
+    expect(source).toContain(".object-browser-scroller {");
+    expect(source).toContain("overflow-x: auto;");
+    expect(source).toContain("min-width: var(--dbx-object-grid-min-width, 0px);");
+  });
+
+  it("clips the header and syncs its scroll position with the scroller", () => {
+    const headerMatch = /ref="objectListHeaderRef"[^>]*/.exec(source);
+    expect(headerMatch).not.toBeNull();
+    expect(headerMatch![0]).toContain("overflow-hidden");
+    expect(source).toContain("function syncObjectListHeaderScroll(");
+    expect(source).toContain("header.scrollLeft = el.scrollLeft");
+    // The sync runs on every scroller scroll event, when the scroller (re)attaches,
+    // and whenever the column widths change the content width.
+    const scrollHandler = source.indexOf("function onObjectsScroll(");
+    expect(source.slice(scrollHandler, scrollHandler + 300)).toContain("syncObjectListHeaderScroll()");
+    expect(source).toContain("nextTick(() => syncObjectListHeaderScroll())");
+  });
+});