feat(client): one source for the footer links, and dialog buttons on the type ramp (UI/UX v3 P4c)

[mizu-jun]

What this closes

The P4 design spec's §8 deferred two surfaces — the settings footer's ↗ Open config.toml / ↺ Reset category links and the dialog button labels — and gave one reason for both: "they are sized from their label widths and those widths reach click targets, so they need hit-region work."

Measuring first shows that reason holds for one of them.

The footer links — the real hit-region work

Their geometry existed twice, label formatting included:

• overlay/settings/mod.rs:708,734 — visual_width(&label) as f32 * cell_w
• event_handler/settings_panel_hit.rs:145,155 — a copy of the same expression

A proportional label's width is not a multiple of cell_w, so moving these to the P4b ramp with the formula mirrored would have drifted the click target away from the glyphs silently.

New overlay/settings/footer.rs owns the labels, the ramp step, the measurement and the rects. footer_links is the single call the builder draws from and the hit-test tests against; the pure place_links underneath takes measured widths, the shape place_tooltip established in P4b. hit_test_settings_panel becomes &mut self so it measures through the same FontManager — one cached run per mouse event over an open panel.

The dialog buttons — the premise was wrong

mouse.rs never references pending_consent or close_window_dialog. Both dialogs are driven by the keyboard (input_handler/mod.rs:46,58) and by AccessKit (accessibility.rs:213,224 write selected / selected_button). A button label's width reaches its own box and nothing else.

So this half is plain typography: box widths come from measure_run at the ramp's Body step, padding (1.5 / 3 cells) and gaps (0.5 / 0.8) unchanged, labels centred from the measured run. One fix falls out — the row reserved n gaps instead of n - 1, leaving it half a gap off centre.

Gates

• Structural: neither the builder nor the hit-test may reconstruct a footer label or call footer_links more than once, and no dialog button may be sized from visual_width again.
• Placement: right-alignment, the inter-link gap, non-overlap, equal padding, a fractional (non-cell) width carried through unrounded, and no phantom reset rect for a non-resettable category — all pure, no device.
• The now-stale #[allow(dead_code)] markers on measure_run / truncate_run_to_width / add_run_verts are removed with their last non-adopting caller.

Verification

• cargo fmt --check — clean
• cargo clippy --workspace --all-targets -- -D warnings — no warnings
• cargo test --workspace — 28 suites pass, 7 new tests
• Not covered: appearance. The links and both dialogs' button rows change size on screen; this joins the P4/P5/P6 on-device backlog.

Noted, deliberately not fixed

The footer links have no AccessKit node at all — accessibility.rs never mentions them, so a screen-reader user cannot reach "Open config.toml" or "Reset category". That is a P6c-shaped accessibility gap rather than a P4 typography one and belongs in its own change; it is recorded in the spec's new §8.1.

🤖 Generated with Claude Code

[github-actions]

Coverage report

Generated by cargo llvm-cov (workspace minus nexterm-client-gpu and nexterm-i18n).