feat(ui): hide GCG export in honest-AI games

A vs_ai game is throwaway practice, so its finished history header no longer
offers the 📤 GCG export (an empty slot keeps the comms icon pinned right).
Docs note the AI exclusion; UI_DESIGN also records that confirming a resign
reveals the full board (closes the history drawer, zooms out).

ui/e2e/quickmatch.spec.ts

@@ -59,6 +59,29 @@ test('AI game: 🤖 opponent, no wait, chat disabled, dictionary still works', a
   await expect(page.locator('.check input')).toBeEnabled();
 });
 
+// GCG export is pointless for a practice AI game, so the finished AI game hides the 📤 export
+// (the comms hub stays). Start an AI game, resign it, reopen the history and check the header.
+test('AI game: no GCG export offered after it ends', async ({ page }) => {
+  await page.goto('/');
+  await page.getByRole('button', { name: /guest/i }).click();
+  await page.getByRole('button', { name: /New/ }).click();
+  await page.locator('.variant').first().click(); // AI is the default opponent
+  await page.getByRole('button', { name: /Start game/i }).click();
+  await expect(page.locator('.scoreboard').getByText('🤖')).toBeVisible();
+
+  // Resign the practice game from the history header.
+  await page.locator('.scoreboard').click();
+  await page.getByRole('button', { name: 'Drop game' }).click();
+  await page.locator('button.danger').click();
+  await expect(page.locator('.status .over')).toBeVisible();
+
+  // Reopen the history (resigning auto-closed it): the finished AI game offers no GCG export,
+  // while the comms hub stays reachable.
+  await page.locator('.scoreboard').click();
+  await expect(page.getByRole('button', { name: 'Export GCG' })).toHaveCount(0);
+  await expect(page.getByRole('button', { name: 'Chat' })).toBeVisible();
+});
+
 // The opponent_joined push is best-effort and never replayed, so a join that lands while the live
 // stream is down is lost. The waiting game screen recovers it without a push: a poll while the
 // stream is down, and a refetch on stream reconnect. The __stream hook (lib/app.svelte.ts) drops /

ui/src/game/Game.svelte

@@ -986,7 +986,13 @@
   {#if view}
     <div class="hhead">
       {#if gameOver}
-        <button class="hicon" onclick={exportGcg} aria-label={t('game.exportGcg')}>📤</button>
+        {#if view.game.vsAi}
+          <!-- GCG export is not offered for a practice AI game; an empty slot keeps the comms
+               icon pinned right (the header is space-between). -->
+          <span aria-hidden="true"></span>
+        {:else}
+          <button class="hicon" onclick={exportGcg} aria-label={t('game.exportGcg')}>📤</button>
+        {/if}
       {:else}
         <button class="hicon" onclick={() => (resignOpen = true)} disabled={waitingForOpponent} aria-label={t('game.dropGame')}>🏁</button>
       {/if}