feat(app-iced): M76 选择类家族 —— Checkbox / Radio / Switch / Chip（15 §18/§19 + 12b §10/§13）

- selection/：geometry（令牌→像素，缺档登记 G16）/ paint（Interaction×选中×错误→角色）/
  shell（48 透明外壳 + 帧内状态通道 + 勾形 SVG）/ checkbox·radio·switch·chip / matrix（12×5 状态矩阵）/ tests
- gallery/selection.rs：小节 + **渲染层像素断言**（20×20 选中与未选中同尺寸 · Radio 内点 10 ·
  Ø40 状态层是圆 · 勾形 14.8 · 短横 · 轨道 52×32 · Chip 32 · 禁用 38%），按颜色+墨迹块定位、不假设行号
- gallery/mod.rs：新增 ULL_GALLERY_SECTION 段落过滤（tower 批准，M77 零成本复用）+ 四个 helper 放宽到 pub(crate)

A1 证据（本机 AAR javap）：未选中 hover/focus/pressed 描边是 OnSurface（不是 OnSurfaceVariant）、
Radio 选中态 hover 仍 Primary、Checkbox SelectedDisabledIconColor=Surface、Switch hover 滑块 PrimaryContainer。

crates/app-iced/src/components/selection/tests.rs

@@ -0,0 +1,307 @@
+//! 选择类家族的单测：几何取自令牌、角色取自 A1（`#[cfg(test)]` 下的纯值断言）。
+//!
+//! **这些测试测的是「值与映射」**——它们抓不住「函数对、图错」（M68 的教训），
+//! 像素级几何在 `components/gallery/selection.rs` 的 `probe` 里对着真截图量。
+
+use unlucky_design::color::{Role, SchemeFlavor};
+use unlucky_design::typography::Platform;
+
+use super::super::interaction::Interaction;
+use super::geometry::{ChipGeometry, ControlGeometry, SwitchGeometry};
+use super::paint::{self, ChipVariant};
+use crate::theme::{Families, Ui};
+
+const FAMILIES: Families = Families {
+    text: "Segoe UI",
+    display: "Segoe UI",
+    mono: "Consolas",
+};
+
+fn ui() -> Ui {
+    Ui::with_platform(SchemeFlavor::Light, Platform::Windows, FAMILIES)
+}
+
+/// §18.1 / §18.5 / §18.9：Checkbox 的四个参考值全部来自令牌层。
+#[test]
+fn checkbox_geometry_comes_from_the_token_layer() {
+    let ui = ui();
+    let g = ControlGeometry::checkbox(&ui);
+    assert_eq!(g.side, 20.0, "18.1：容器 20×20（ContainerWidth=18 是死值）");
+    assert_eq!(g.radius, 2.0, "18.1：圆角 2（ComponentRadius::Micro）");
+    assert_eq!(g.stroke, 2.0, "18.2：未选中描边 2px");
+    assert_eq!(g.state_layer, 40.0, "18.5：状态层 Ø40");
+    assert_eq!(g.hit, 48.0, "18.9：命中区 48");
+    assert_eq!(g.gap, 8.0, "18.9：框↔标签 8（[估] 团队口径）");
+    assert_eq!(g.inner_dot, 0.0, "Checkbox 没有内点");
+    // 18.4：勾形横向端点跨度 = 0.8−0.2 = 0.6 × 20 = 12
+    assert!((g.check_span() - 12.0).abs() < 0.001, "18.4：勾横向 12dp");
+    // 方头外扩：每端 2/√2 ≈ 1.41 → 墨迹跨度 ≈ 14.8（参考值 12 是端点跨度，不是墨迹）
+    let bleed = g.square_cap_bleed();
+    assert!(
+        (bleed - std::f32::consts::SQRT_2).abs() < 0.001,
+        "方头外扩 1/√2×线宽"
+    );
+    assert!(
+        (g.check_span() + bleed * 2.0 - 14.83).abs() < 0.05,
+        "墨迹跨度 ≈14.83"
+    );
+}
+
+/// §19.1 / §19.2：Radio 外圈 20、环线 2、**内点 10 不是 12**、真圆。
+#[test]
+fn radio_inner_dot_is_ten_not_twelve() {
+    let ui = ui();
+    let g = ControlGeometry::radio(&ui);
+    assert_eq!(g.side, 20.0, "19.1：外圈直径 20");
+    assert_eq!(g.stroke, 2.0, "19.1：环线 2px");
+    assert_eq!(g.radius, 10.0, "19.1：真圆（半径 = 边长/2）");
+    assert_eq!(g.inner_dot, 10.0, "19.2：内点可视直径 10");
+    assert_ne!(
+        g.inner_dot, 12.0,
+        "19.2：12 是含描边前的名义值，抄 12 会明显偏大"
+    );
+    assert_eq!(g.state_layer, 40.0, "19.7：状态层 Ø40");
+    assert_eq!(g.hit, 48.0, "19.7：命中区 48");
+}
+
+/// §10.1 / §10.2 / §10.6：Switch 的三档滑块与状态层，以及「状态层必然溢出轨道」这条布局不变量。
+#[test]
+fn switch_geometry_matches_the_tokens() {
+    let ui = ui();
+    let g = SwitchGeometry::of(&ui);
+    assert_eq!(g.track_width, 52.0, "10.1：轨道宽 52");
+    assert_eq!(g.track_height, 32.0, "10.1：轨道高 32");
+    assert_eq!(g.track_stroke, 2.0, "10.3：未选中态 2px Outline");
+    assert_eq!(g.thumb(false, false), 16.0, "10.2：未选中滑块 16");
+    assert_eq!(g.thumb(true, false), 24.0, "10.2：选中滑块 24");
+    assert_eq!(g.thumb(false, true), 28.0, "10.2：按下滑块 28");
+    assert_eq!(g.thumb(true, true), 28.0, "10.2：按下档与选中无关");
+    assert_eq!(g.icon, 16.0, "10.5：滑块内图标 16");
+    assert_eq!(g.state_layer, 40.0, "10.6：状态层 Ø40");
+    assert_eq!(g.hit, 48.0, "命中区 48");
+
+    // 内距公式在三个档位都成立（32−24=8→4、32−16=16→8、32−28=4→2）
+    for thumb in [24.0, 16.0, 28.0] {
+        assert!((g.thumb_inset(thumb) * 2.0 + thumb - g.track_height).abs() < 0.001);
+    }
+    // 状态层必然溢出轨道左右：未选中时滑块靠左、选中时靠右
+    assert_eq!(g.bleed(), 4.0, "状态层比轨道高 → 上下各溢出 4");
+    assert_eq!(g.draw_width(), 60.0, "绘制区宽 = 52 + 2×4");
+    for (selected, thumb) in [(false, 16.0), (true, 24.0), (false, 28.0), (true, 28.0)] {
+        let offset = g.layer_offset(selected, thumb);
+        assert!(
+            offset >= 0.0,
+            "状态层左缘不得为负（selected={selected} thumb={thumb} → {offset}）"
+        );
+        // 圆心与滑块同心：offset + 半径 = 滑块圆心 + 外扩
+        let center = offset + g.layer_radius();
+        assert!((center - (g.thumb_center(selected, thumb) + g.bleed())).abs() < 0.001);
+    }
+}
+
+/// §13.1 / §13.3 / §13.4：Chip 高 32、圆角 8、内边距 8、图标 16（官方 18 → G14）。
+#[test]
+fn chip_geometry_matches_the_tokens() {
+    let ui = ui();
+    let g = ChipGeometry::of(&ui);
+    assert_eq!(g.height, 32.0, "13.1：容器高 32");
+    assert_eq!(g.radius, 8.0, "13.1：圆角 8（ContainerShape=CornerSmall）");
+    assert_eq!(g.pad, 8.0, "13.3：水平内边距 8");
+    assert_eq!(g.gap, 8.0, "13.3：元素间距 8");
+    assert_eq!(g.icon, 16.0, "13.4：图标 16（官方 18 → G14 偏离）");
+}
+
+/// §18.2 / A1：未选中 Checkbox 在 hover/focus/pressed 下描边提到 `OnSurface`（不是 `OnSurfaceVariant`）。
+#[test]
+fn checkbox_unselected_lifts_the_outline_to_on_surface() {
+    let ui = ui();
+    let g = ControlGeometry::checkbox(&ui);
+    let at_rest = paint::checkbox(&ui, false, false, Interaction::Enabled, g.radius, g.stroke);
+    assert_eq!(
+        at_rest.frame.outline,
+        Some(ui.color(Role::OnSurfaceVariant))
+    );
+    for state in [
+        Interaction::Hovered,
+        Interaction::Focused,
+        Interaction::Pressed,
+    ] {
+        let lifted = paint::checkbox(&ui, false, false, state, g.radius, g.stroke);
+        assert_eq!(
+            lifted.frame.outline,
+            Some(ui.color(Role::OnSurface)),
+            "A1：{state:?} 的 UnselectedOutlineColor = OnSurface"
+        );
+        assert_eq!(lifted.frame.stroke, 2.0, "18.8：描边宽度不随态变");
+    }
+    // 错误态优先于 hover
+    let error = paint::checkbox(&ui, false, true, Interaction::Hovered, g.radius, g.stroke);
+    assert_eq!(error.frame.outline, Some(ui.color(Role::Error)));
+}
+
+/// §18.8：禁用不是「变淡变细」——描边仍 2；选中禁用是 `OnSurface`@38% 容器 + `Surface` 勾。
+#[test]
+fn checkbox_disabled_keeps_the_stroke_and_uses_the_a1_roles() {
+    let ui = ui();
+    let g = ControlGeometry::checkbox(&ui);
+    let unchecked = paint::checkbox(&ui, false, false, Interaction::Disabled, g.radius, g.stroke);
+    assert_eq!(unchecked.frame.stroke, 2.0, "18.8：禁用描边仍 2px");
+    assert_eq!(unchecked.frame.fill, None, "18.8：未选中禁用内部仍透明");
+    assert!(
+        unchecked
+            .frame
+            .outline
+            .is_some_and(|color| color != ui.color(Role::OnSurfaceVariant)),
+        "18.8：禁用描边是 OnSurface@38%，不是满档角色色"
+    );
+
+    let checked = paint::checkbox(&ui, true, false, Interaction::Disabled, g.radius, g.stroke);
+    assert_eq!(
+        checked.glyph,
+        ui.color(Role::Surface),
+        "A1：SelectedDisabledIconColor = Surface"
+    );
+    assert!(checked.frame.fill.is_some());
+    assert_ne!(
+        checked.frame.fill,
+        Some(ui.color(Role::Primary)),
+        "禁用不保留 Primary"
+    );
+}
+
+/// §19.4：**选中态 hover/pressed 不换环色**（只有状态层变）。
+#[test]
+fn radio_keeps_primary_on_hover_when_selected() {
+    let ui = ui();
+    let g = ControlGeometry::radio(&ui);
+    let primary = Some(ui.color(Role::Primary));
+    for state in Interaction::ALL {
+        if state.is_disabled() {
+            continue;
+        }
+        let paint = paint::radio(&ui, true, state, g.radius, g.stroke);
+        assert_eq!(
+            paint.ring.outline, primary,
+            "19.4：{state:?} 环仍是 Primary"
+        );
+        assert_eq!(paint.dot, primary, "19.4：{state:?} 点仍是 Primary");
+    }
+    // 未选中：静息 OnSurfaceVariant → hover/focus/pressed 提到 OnSurface
+    let at_rest = paint::radio(&ui, false, Interaction::Enabled, g.radius, g.stroke);
+    assert_eq!(at_rest.dot, None, "未选中不画内点");
+    assert_eq!(at_rest.ring.outline, Some(ui.color(Role::OnSurfaceVariant)));
+    let lifted = paint::radio(&ui, false, Interaction::Hovered, g.radius, g.stroke);
+    assert_eq!(lifted.ring.outline, Some(ui.color(Role::OnSurface)));
+}
+
+/// §10.4 + A1：选中态 hover 的滑块是 `PrimaryContainer`；禁用选中滑块是 `Surface`（不透明度 1）。
+#[test]
+fn switch_handle_roles_follow_the_tokens() {
+    let ui = ui();
+    let at_rest = paint::switch(&ui, true, Interaction::Enabled);
+    assert_eq!(at_rest.track.fill, Some(ui.color(Role::Primary)));
+    assert_eq!(at_rest.thumb, ui.color(Role::OnPrimary));
+    assert_eq!(at_rest.icon, Some(ui.color(Role::OnPrimaryContainer)));
+
+    let hovered = paint::switch(&ui, true, Interaction::Hovered);
+    assert_eq!(
+        hovered.thumb,
+        ui.color(Role::PrimaryContainer),
+        "A1：选中 hover 滑块 PrimaryContainer"
+    );
+    assert_eq!(
+        hovered.track.fill,
+        Some(ui.color(Role::Primary)),
+        "轨道不随 hover 变"
+    );
+
+    let off = paint::switch(&ui, false, Interaction::Enabled);
+    assert_eq!(
+        off.track.outline,
+        Some(ui.color(Role::Outline)),
+        "10.3：未选中 2px Outline"
+    );
+    assert_eq!(off.track.stroke, 2.0);
+    assert_eq!(
+        off.thumb,
+        ui.color(Role::Outline),
+        "10.4：未选中滑块 Outline"
+    );
+    assert_eq!(off.icon, None, "未选中态图标与轨道同色（不画）");
+
+    let disabled = paint::switch(&ui, true, Interaction::Disabled);
+    assert_eq!(
+        disabled.thumb,
+        ui.color(Role::Surface),
+        "A1：DisabledSelectedHandleColor=Surface"
+    );
+}
+
+/// §13.5 / §13.6 / §13.7：选中态**无描边**、Assist 不可选中、禁用文字 @38%。
+#[test]
+fn chip_roles_follow_the_tokens() {
+    let ui = ui();
+    let radius = ChipGeometry::of(&ui).radius;
+
+    let selected = paint::chip(&ui, ChipVariant::Filter, true, Interaction::Enabled, radius);
+    assert_eq!(
+        selected.frame.fill,
+        Some(ui.color(Role::SecondaryContainer))
+    );
+    assert_eq!(selected.frame.outline, None, "13.5：选中描边 0dp");
+    assert_eq!(selected.label, ui.color(Role::OnSecondaryContainer));
+
+    let unselected = paint::chip(
+        &ui,
+        ChipVariant::Filter,
+        false,
+        Interaction::Enabled,
+        radius,
+    );
+    assert_eq!(
+        unselected.frame.outline,
+        Some(ui.color(Role::OutlineVariant))
+    );
+    assert_eq!(unselected.label, ui.color(Role::OnSurfaceVariant));
+
+    // Assist 没有选中态：即使传 selected = true 也不会变 SecondaryContainer
+    let assist = paint::chip(&ui, ChipVariant::Assist, true, Interaction::Enabled, radius);
+    assert_ne!(assist.frame.fill, Some(ui.color(Role::SecondaryContainer)));
+    assert_eq!(
+        assist.icon,
+        ui.color(Role::Primary),
+        "13.4：Assist 前置图标 Primary"
+    );
+
+    let disabled = paint::chip(
+        &ui,
+        ChipVariant::Filter,
+        false,
+        Interaction::Disabled,
+        radius,
+    );
+    assert_ne!(disabled.label, unselected.label, "13.7：禁用文字降到 38%");
+}
+
+/// 状态层只在三态存在，且**不是**满档角色色（α 由 `interaction` 给）。
+#[test]
+fn state_layer_only_exists_on_lifted_states() {
+    let ui = ui();
+    for (state, expected) in [
+        (Interaction::Enabled, false),
+        (Interaction::Hovered, true),
+        (Interaction::Focused, true),
+        (Interaction::Pressed, true),
+        (Interaction::Disabled, false),
+    ] {
+        let layer = paint::state_layer(&ui, state, Role::OnSurfaceVariant);
+        assert_eq!(layer.is_some(), expected, "{state:?} 的状态层有无");
+        if let Some(color) = layer {
+            assert_eq!(color.a, 1.0, "状态层必须是实色（D27：CPU/GPU 一致）");
+        }
+    }
+    // 同态下 hover 比 pressed 浅（8% < 10%）
+    let hover = paint::state_layer(&ui, Interaction::Hovered, Role::OnSurface).unwrap();
+    let pressed = paint::state_layer(&ui, Interaction::Pressed, Role::OnSurface).unwrap();
+    assert_ne!(hover, pressed);
+}