[binlecode]

Summary

Net and disk I/O rates shipped in 1.8.0 as two plain text rows tacked onto the bottom of the Memory box — the only telemetry in the dashboard with no history rendering, and mis-filed (network throughput is not a memory metric). They now own two sibling sections, each drawing a mirrored in-over-out chart pair whose seam reads as a shared zero axis (btop/vnstat convention).

╭─ Network ─────────────────────────────╮╭─ Disk ────────────────────────────────╮
│ ↓ In 29.8 KB/s   avg 5.5 · max 29.8   ││ ↓ Read 6.2 MB/s   avg 782 KB · max 6.2│
│ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀  ││ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀  │
│ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⢀  ││ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸  │  ← up-trace anchored at the seam
│ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠃⠀⠁⠈  ││ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠁⠹⠸  │  ← down-trace hanging from it
│ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀  ││ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀  │
│ ↑ Out 40.4 KB/s  avg 33.1 · max 186.4 ││ ↑ Write 3.2 MB/s  avg 875 KB · max 3.2│
╰───────────────────────────────────────╯╰───────────────────────────────────────╯

Six content rows — identical height to two separate label+chart stacks, and each direction keeps its own avg · max. No axis row is drawn: the seam is the axis.

Behavior change

• Grid gains a third paired row (Network | Disk); Power keeps its full-width span beneath. Each section hides itself entirely when the platform reports no counters, so Power closes the gap on a machine without them.
• Charts are always auto-scaled. There is no SoC reference throughput for a NIC or NVMe controller, so --power-scale profile has no analogue here. New L2 helper analytics.io_rate_percent() divides by max(floor, rolling_peak x1.25), reusing the multiplier --power-scale auto already uses. Both directions of a box share one denominator, so an upload trickle never renders as tall as a saturating download.
• New floors NET_RATE_FLOOR_BPS (1 MB/s) and DISK_RATE_FLOOR_BPS (10 MB/s) stop idle background chatter (mDNS keepalives, APFS journaling) from dividing by itself and painting a full-scale chart.
• BrailleChart gains fill. down anchors the trace at the top edge via a second cumulative bit table — exact in dots; in block the downward half quantizes to 2 levels/row, since Block Elements ships only ▀/█ as upper fills and the quarter-blocks at U+1FB82/U+1FB85 are missing from many terminal fonts. A coarser trace that always draws beats a finer one that renders as tofu.
• No alert threshold added — neither bus has a knowable ceiling to saturate against, so AlertEngine is untouched.
• Export output is unchanged. Presentation only; --json / --serve fields are identical.
• Cover page: version badge and footer (both carried a doubled v — vv1.7.0), plus a net/disk feature card.

Tested

Ventura-era macOS 15 (Darwin 25.5.0) + Apple M4 Max (4E+12P+40GPU).

.venv/bin/python -m ruff check --fix . && .venv/bin/python -m ruff format .
.venv/bin/python -m actop.actop --help
.venv/bin/pytest -q          # 149 passed

Rendered live against real hardware at 130x46 (grid, 4 rows, paired boxes bottom-aligned) and 88x44 (grid correctly auto-degrading to scrolling stack under the 96-col threshold). Both I/O sections populate from live counters; the floors visibly damp idle chatter as designed.

Tests

Three new functional tests, all driving public surfaces:

• test_down_fill_hangs_the_trace_from_the_top_edge — a partial reading fills the top rows in down mode and the bottom rows in up. Catches the mirror silently inverting into two identical traces with a gap down the middle; nothing else looks at fill direction.
• test_down_fill_block_mode_uses_upper_block_glyphs — pins the ▀/█ ramp so a future move to the legacy-computing quarter-blocks has to be deliberate rather than a silent tofu regression.
• test_io_rate_percent_floor_keeps_idle_chatter_off_full_scale — the noise-amplification failure the floors exist to prevent.

test_net_disk_sections_show_rates_and_scaled_charts_when_available now drives two samples and asserts the chart carries percents against the shared peak-based denominator (80% → 20%), catching a chart wired to the native-unit deque instead of the percent deque.

Docs

docs/SPEC-system.md §6.1 (grid row composition), §6.2 (fill direction + block tradeoff), §6.5 (rewritten for the mirror, including the asymmetric-availability behavior); CLAUDE.md module table and data-flow paragraph (five → seven sections); help overlay metric labels and grid description; CHANGELOG.md; docs/ROADMAP.md N2.

🤖 Generated with Claude Code