style(HistoryListPanel): match ServerListScreen Export button — rename + default variant

Renames "Export JSON" to "Export" and switches from the subtle ToolbarButton
to the same `Button variant="default"` used by ServerListControls so the
two Export affordances look identical across screens. Also moves the
button to the right of the ListToggle (mirroring the order on the server
list screen) and disables it when there are no entries to export.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cliffhall

clients/web/src/components/groups/HistoryListPanel/HistoryListPanel.test.tsx

@@ -69,12 +69,10 @@ const baseProps = {
 };
 
 describe("HistoryListPanel", () => {
-  it("renders the title and Export JSON button", () => {
+  it("renders the title and Export button", () => {
     renderWithMantine(<HistoryListPanel {...baseProps} entries={[]} />);
     expect(screen.getByText("Requests")).toBeInTheDocument();
-    expect(
-      screen.getByRole("button", { name: "Export JSON" }),
-    ).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Export" })).toBeInTheDocument();
   });
 
   it("renders the empty state when there are no entries", () => {
@@ -134,7 +132,7 @@ describe("HistoryListPanel", () => {
     expect(screen.getByText("History (1)")).toBeInTheDocument();
   });
 
-  it("invokes onExport when Export JSON is clicked", async () => {
+  it("invokes onExport when Export is clicked", async () => {
     const user = userEvent.setup();
     const onExport = vi.fn();
     renderWithMantine(
@@ -144,7 +142,7 @@ describe("HistoryListPanel", () => {
         onExport={onExport}
       />,
     );
-    await user.click(screen.getByRole("button", { name: "Export JSON" }));
+    await user.click(screen.getByRole("button", { name: "Export" }));
     expect(onExport).toHaveBeenCalledTimes(1);
   });
 

clients/web/src/components/groups/HistoryListPanel/HistoryListPanel.tsx

@@ -101,13 +101,15 @@ export function HistoryListPanel({
       <Group justify="space-between" mb="sm">
         <Title order={4}>Requests</Title>
         <Group gap="xs">
-          <ToolbarButton onClick={onExport}>Export JSON</ToolbarButton>
           {hasResults && (
             <ListToggle
               compact={compact}
               onToggle={() => setCompact((c) => !c)}
             />
           )}
+          <Button variant="default" onClick={onExport} disabled={!hasResults}>
+            Export
+          </Button>
         </Group>
       </Group>