---
id: TASK-026
title: 'TUI: Network I/O history sparkline on System page'
status: To Do
assignee: []
created_date: '2026-06-12 04:21'
labels:
  - tui
  - feature
dependencies: []
priority: low
ordinal: 26000
---

## Description

<!-- SECTION:DESCRIPTION:BEGIN -->
The CPU sparkline tracks 60 samples of CPU history. Add equivalent sparklines for network bytes-in and bytes-out on the System page.

Implementation:
- Add `net_down_history: deque[float]` and `net_up_history: deque[float]` (maxlen=60) to `SystemStats`
- Append `down` and `up` values in `sample()` (use 0.0 when delta is unavailable)
- Add two `Sparkline` widgets in a row below the CPU sparkline or beside it: "Net ↓" and "Net ↑"
- Border titles show current rate: "Net ↓  1.2 MB/s"
- Match the existing sparkline styling (`color: $accent`, round border)
- Update via the same `_apply_system()` path
<!-- SECTION:DESCRIPTION:END -->

## Acceptance Criteria
<!-- AC:BEGIN -->
- [ ] #1 Two sparklines (download, upload) visible on System page
- [ ] #2 Border titles show current rate in human-readable format
- [ ] #3 History tracks 60 samples at SYS_REFRESH_SECS interval
- [ ] #4 Layout doesn't push process table off screen
<!-- AC:END -->