Summary

Three remote-mode all-smi view bugs from this session, plus a small README polish.

1. Node counter inflated by reserved tabs

The dashboard derived total_nodes as state.tabs.len() - 1, only subtracting "All". The real remote-mode tab layout is [All, Users, Topology, host1, …] (set in remote_collector, ssh_strategy, replay_collector, runner, and event_handler), so a 50-host cluster rendered as 50/52.

Fix: added is_reserved_tab / host_tab_count helpers in src/ui/tabs.rs and switched draw_system_view to count only host tabs. The helper centralizes the reserved-tab list so future cluster-level tabs can't silently inflate the denominator again.

2. Live Statistics ↔ Tabs collision

The remote sparkline panel's last row sat directly above the tab strip, hurting readability. Added one spacer line at the tail of draw_remote_sparkline_panel (inside the empty-history early-return so it only emits when the panel actually renders) and bumped LayoutCalculator::calculate_header_lines from 5 to 6 to keep the content-area math in sync.

3. Topology tab box borders zig-zagging

center() in topology::graph_render measured field width with str::len(), but every edge label uses ─ (U+2500 — 3 bytes / 1 cell). For center("── NV ──", 13) it saw len == 16 ≥ 13 and returned the label untouched at 8 visible cells — 5 short of the cell width. The right │ border then slipped left and the NUMA box looked broken.

Fix: switched to s.chars().count(), which equals display width for the ASCII + single-cell box-drawing characters this module emits, and documented the assumption.

Sample render after the fix (all four lines 54 cells):

┌────────────────────── NUMA 0 ──────────────────────┐
│   [GPU 0]      [GPU 1]      [GPU 2]      [GPU 3]   │
│  ── NV5 ──    ── NV5 ──    ── NV5 ──               │
└────────────────────────────────────────────────────┘

4. README download shields

Both Crates.io and GitHub badges rendered as bare downloads | N, giving no visual cue which count came from which source. They now read crates.io downloads and GitHub downloads.

Tests

• cargo test --lib — 1033 passed, 0 failed.
• cargo clippy --lib --tests -- -D warnings — clean.

Regression coverage added in this PR:

• ui::tabs::tests::host_tab_count_excludes_reserved_tabs — asserts the real [All, Users, Topology, host-0..host-49] shape counts as 50.
• ui::tabs::tests::is_reserved_tab_matches_cluster_level_tabs — pins the reserved-tab list.
• ui::topology::graph_render::tests::center_uses_display_width_not_byte_length — pins every edge label (──, ── NV ──, ── NV5 ──, ── NSW ──, ── PXB ──, ── NODE ──, ── SYS ──) to its requested cell width.
• ui::topology::graph_render::tests::render_numa_box_keeps_borders_aligned_with_unicode_edge_labels — integration check that every border-bearing line of a rendered box has identical visible width.

Risk

Low. Pure rendering / arithmetic fixes; no behavior change for local mode or for the data pipeline. Header-line budget bumped by 1 row so the content area shrinks by one row when Live Statistics is visible.