fix: move help land position (#6571)

Before:
<img width="1614" alt="image" src="https://github.com/toeverything/AFFiNE/assets/58546692/24d4c550-4070-48a5-a851-40d6f26ea120">

After:
<img width="1106" alt="image" src="https://github.com/toeverything/AFFiNE/assets/58546692/88e1b7ea-8a69-45a2-9beb-780dfd1bd996">
<img width="949" alt="image" src="https://github.com/toeverything/AFFiNE/assets/58546692/8fd328c5-e8e8-402a-b18e-436056d2374f">

Cause the icon will be on top of chat input.

packages/frontend/core/src/modules/workbench/view/split-view/split-view.css.ts

@@ -11,6 +11,7 @@ export const splitViewRoot = style({
   },
   display: 'flex',
   flexDirection: 'row',
+  position: 'relative',
   borderRadius,
   gap,
 

packages/frontend/core/src/modules/workbench/view/split-view/split-view.tsx

@@ -1,3 +1,4 @@
+import { HubIsland } from '@affine/core/components/affine/hub-island';
 import { useAppSettingHelper } from '@affine/core/hooks/affine/use-app-setting-helper';
 import type { DragEndEvent } from '@dnd-kit/core';
 import {
@@ -108,6 +109,7 @@ export const SplitView = ({
       data-client-border={appSettings.clientBorder}
       {...attrs}
     >
+      <HubIsland />
       <DndContext
         sensors={sensors}
         collisionDetection={closestCenter}

packages/frontend/core/src/modules/workbench/view/workbench-root.tsx

@@ -1,4 +1,3 @@
-import { HubIsland } from '@affine/core/components/affine/hub-island';
 import { useLiveData, useService } from '@toeverything/infra';
 import { useCallback, useEffect, useRef } from 'react';
 import { useLocation } from 'react-router-dom';
@@ -44,16 +43,12 @@ export const WorkbenchRoot = () => {
   }, [basename, workbench.basename$]);
 
   return (
-    <>
-      <HubIsland />
-
-      <SplitView
-        className={styles.workbenchRootContainer}
-        views={views}
-        renderer={panelRenderer}
-        onMove={onMove}
-      />
-    </>
+    <SplitView
+      className={styles.workbenchRootContainer}
+      views={views}
+      renderer={panelRenderer}
+      onMove={onMove}
+    />
   );
 };