Mobile view: Active jobs section may block access to generated assets in list view

**Issue Description**

On mobile devices, the active jobs section in the assets sidebar list view may exceed the screen height, preventing users from physically accessing the generated assets section below it.

**Context**

This issue was identified during review of the list view implementation for the assets sidepanel. The vertical height comes from portions of the sidebar tab template, and fixing this will likely require changes to both the sidebar tab template and the virtual grid component to properly account for available vertical space.

**References**

- PR: https://github.com/Comfy-Org/ComfyUI_frontend/pull/7737
- Comment: https://github.com/Comfy-Org/ComfyUI_frontend/pull/7737#discussion_r2654565526
- Reported by: @christian-byrne

**Affected Component**

`src/components/sidebar/tabs/AssetsSidebarListView.vue` and related sidebar tab template components

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-7909-Mobile-view-Active-jobs-section-may-block-access-to-generated-assets-in-list-view-2e26d73d365081b98692daedb0b7deac) by [Unito](https://www.unito.io)