feat(settings): shared nebula-settings crate; GPUI lab reads runtime settings + theme term colors

New zero-dependency workspace crate owning nebula_settings.txt path resolution, key semantics and the per-theme terminal color tables (background, light-theme foreground/ANSI-16 replacement, powerline slots 16..=23) - values transcribed verbatim from the legacy shell's theme.rs, which stays frozen per P4. The GPUI lab now honors the user's actual runtime intent: theme (SilverLight etc.) applied over toml colors in the same order as apply_term_colors, font family/size from the settings UI, default cursor shape/blink wired into the engine Term config, copy_on_select exposed for the next slice. Cargo.lock intentionally not committed: it currently carries the user's in-flight gpui-fork switch.

Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "nebula-completions",
     "nebula_hook",
     "nebula_gpui",
+    "nebula_settings",
 ]
 resolver = "2"
 

nebula_gpui/Cargo.toml

@@ -24,6 +24,8 @@ gpui-component-assets = "=0.5.1"
 # 终端核心是纯 Rust（vte/grid/ConPTY），没有 GUI 原生依赖，因此可以跨 workspace
 # 边界直接 path 引用而不会重新引入 fontconfig links 冲突。
 nebula_terminal = { path = "../nebula_terminal" }
+# 运行时用户设置（nebula_settings.txt + 主题终端色表）的共享权威实现。
+nebula-settings = { path = "../nebula_settings" }
 futures = "0.3"
 # 读取用户 nebula.toml 的字体/配色子集；版本与主仓保持一致。
 serde = { version = "1", features = ["derive"] }

nebula_gpui/src/config/mod.rs

@@ -1,18 +1,26 @@
-//! 读取用户的 `nebula.toml`，与 `nebula_app` 共享同一份配置文件。
+//! 读取用户配置：`nebula.toml` + `nebula_settings.txt`，与 `nebula_app`
+//! 共享同一套文件与语义。
 //!
-//! 只解析 GPUI 壳当前消费的子集（字体、终端配色），解析全程宽容：未知字段
-//! 忽略、非法值回退默认，保证任何用户配置都不会阻止启动。查找路径与主应用
-//! `config::installed_config` 完全一致；`general.import`（及顶层 `import`）
-//! 按主应用语义做值级合并：imports 先加载，主文件最后覆盖。
+//! 两个来源、一个优先级：`nebula_settings.txt`（设置界面持久化的运行时
+//! 意图，经共享 crate `nebula-settings` 读取）覆盖 `nebula.toml` 的对应
+//! 字段；主题对终端色表的影响永远在最后叠加（镜像旧壳 `apply_term_colors`
+//! 的次序：用户配色是 defaults，主题裁定背景/浅色替换/Powerline 槽位）。
+//!
+//! 解析全程宽容：未知字段忽略、非法值回退默认，任何用户配置都不会阻止
+//! 启动。toml 查找路径与主应用 `config::installed_config` 一致；
+//! `general.import`（及顶层 `import`）按主应用语义值级合并。
 //!
 //! 尚未对齐的字段（记录在案，后续步骤处理）：
 //! - `font.offset` / `font.glyph_offset`（cell 度量微调）
 //! - `colors.cursor` 的 `CellForeground`/`CellBackground` 反色语义
+//! - `follow_system_theme`（系统外观联动切主题）
 //! - 配置热重载（主应用用 notify 监视；本壳目前启动读一次）
 
 use std::path::{Path, PathBuf};
 
 use gpui::Global;
+use nebula_settings::{CursorShapeName, RuntimeSettings};
+use nebula_terminal::vte::ansi::CursorShape;
 use serde::Deserialize;
 
 use crate::terminal::colors::Palette;
@@ -26,7 +34,11 @@ pub struct Settings {
     /// GPUI 逻辑像素（配置里是 pt，1pt = 4/3 px @96dpi）。
     pub font_size_px: f32,
     pub palette: Palette,
-    /// 实际加载的配置文件（诊断用；None 表示全默认）。
+    pub cursor_shape: Option<CursorShape>,
+    pub cursor_blink: Option<bool>,
+    /// 选区完成即复制（旧壳 `copy_on_select` 设置）。
+    pub copy_on_select: bool,
+    /// 实际加载的 toml 配置文件（诊断用；None 表示无 toml）。
     pub source_path: Option<PathBuf>,
 }
 
@@ -34,6 +46,7 @@ impl Global for Settings {}
 
 impl Settings {
     pub fn load() -> Self {
+        let runtime = RuntimeSettings::load();
         let path = find_config_file();
         let raw = path
             .as_deref()
@@ -41,26 +54,82 @@ impl Settings {
             .unwrap_or_else(|| toml::Value::Table(Default::default()));
         let raw: RawConfig = raw.try_into().unwrap_or_default();
 
-        let normal_family = raw
-            .font
-            .normal
-            .family
+        // 字体：settings.txt（设置界面）覆盖 toml，最后落内置默认。
+        let normal_family = runtime
+            .font_family
             .clone()
+            .or_else(|| raw.font.normal.family.clone())
             .unwrap_or_else(|| default_font_family().to_string());
         let secondary = |desc: &RawFontDesc| -> String {
             desc.family.clone().unwrap_or_else(|| normal_family.clone())
         };
+        let font_size_pt =
+            runtime.font_size_pt.or(raw.font.size).unwrap_or(11.25).clamp(4.0, 96.0);
+
+        // 配色：toml 覆盖内置默认，主题最后裁定（与旧壳同序）。
+        let mut palette = build_palette(&raw.colors);
+        apply_theme(&mut palette, runtime.theme);
 
         Settings {
             font_bold_family: secondary(&raw.font.bold),
             font_italic_family: secondary(&raw.font.italic),
             font_bold_italic_family: secondary(&raw.font.bold_italic),
-            font_size_px: raw.font.size.unwrap_or(11.25).clamp(4.0, 96.0) * 4.0 / 3.0,
-            palette: build_palette(&raw.colors),
+            font_size_px: font_size_pt * 4.0 / 3.0,
+            palette,
+            cursor_shape: runtime.cursor_shape.map(|shape| match shape {
+                CursorShapeName::Block => CursorShape::Block,
+                CursorShapeName::Beam => CursorShape::Beam,
+                CursorShapeName::Underline => CursorShape::Underline,
+            }),
+            cursor_blink: runtime.cursor_blink,
+            copy_on_select: runtime.copy_on_select,
             font_family: normal_family,
             source_path: path,
         }
     }
+
+    /// 引擎 Term 的启动配置（默认光标形状/闪烁来自运行时设置）。
+    pub fn term_config(&self) -> nebula_terminal::term::Config {
+        let mut config = nebula_terminal::term::Config::default();
+        if let Some(shape) = self.cursor_shape {
+            config.default_cursor_style.shape = shape;
+        }
+        if let Some(blinking) = self.cursor_blink {
+            config.default_cursor_style.blinking = blinking;
+        }
+        config
+    }
+}
+
+/// 主题叠加在 toml 配色之上（镜像旧壳 `apply_term_colors` 的范围与次序）：
+/// 背景永远替换；Powerline 槽位 16..=23 替换；浅色主题另替换前景与
+/// ANSI-16。dim 表与 bright_foreground 有意不动——与旧壳逐字段一致。
+fn apply_theme(palette: &mut Palette, theme: nebula_settings::ThemeName) {
+    let term = theme.term_theme();
+    palette.background = rgba8(term.background);
+    for (i, color) in term.powerline.into_iter().enumerate() {
+        set_indexed(palette, nebula_settings::POWERLINE_SLOT0 + i as u8, rgba8(color));
+    }
+    if term.is_light {
+        palette.foreground = rgba8(nebula_settings::LIGHT_FOREGROUND);
+        for (i, color) in nebula_settings::LIGHT_ANSI.into_iter().enumerate() {
+            palette.ansi[i] = rgba8(color);
+        }
+    }
+}
+
+fn set_indexed(palette: &mut Palette, index: u8, color: gpui::Rgba) {
+    palette.indexed.retain(|(existing, _)| *existing != index);
+    palette.indexed.push((index, color));
+}
+
+fn rgba8(color: nebula_settings::Rgb8) -> gpui::Rgba {
+    gpui::Rgba {
+        r: color[0] as f32 / 255.0,
+        g: color[1] as f32 / 255.0,
+        b: color[2] as f32 / 255.0,
+        a: 1.0,
+    }
 }
 
 fn default_font_family() -> &'static str {

nebula_gpui/src/terminal/session.rs

@@ -50,9 +50,11 @@ pub struct TerminalSession {
     pub notifier: Notifier,
 }
 
-/// 启动一个本地 shell 会话。尺寸随后由首帧 prepaint 按真实布局重设。
+/// 启动一个本地 shell 会话。尺寸随后由首帧 prepaint 按真实布局重设；
+/// `term_config` 携带运行时设置（默认光标形状/闪烁等）。
 pub fn spawn(
     window_size: WindowSize,
+    term_config: Config,
 ) -> std::io::Result<(TerminalSession, UnboundedReceiver<Event>)> {
     let (tx, rx) = unbounded();
     let proxy = EventProxy(tx);
@@ -61,7 +63,7 @@ pub fn spawn(
         columns: window_size.num_cols as usize,
         screen_lines: window_size.num_lines as usize,
     };
-    let term = Arc::new(FairMutex::new(Term::new(Config::default(), &grid, proxy.clone())));
+    let term = Arc::new(FairMutex::new(Term::new(term_config, &grid, proxy.clone())));
 
     let options = tty::Options::default();
     tty::setup_env();

nebula_gpui/src/terminal/view.rs

@@ -62,8 +62,9 @@ pub struct TerminalView {
 
 impl TerminalView {
     pub fn new(cx: &mut Context<Self>) -> Self {
-        // 字体与调色板来自用户 nebula.toml（bootstrap 时装载为全局 Settings）。
-        let (families, font_size, palette) = match cx.try_global::<Settings>() {
+        // 字体、调色板与终端启动配置来自用户配置（nebula.toml +
+        // nebula_settings.txt，bootstrap 时装载为全局 Settings）。
+        let (families, font_size, palette, term_config) = match cx.try_global::<Settings>() {
             Some(settings) => (
                 [
                     settings.font_family.clone(),
@@ -73,11 +74,13 @@ impl TerminalView {
                 ],
                 px(settings.font_size_px),
                 Arc::new(settings.palette.clone()),
+                settings.term_config(),
             ),
             None => (
                 std::array::from_fn(|_| String::from("Cascadia Mono")),
                 px(15.0),
                 Arc::new(Palette::default()),
+                nebula_terminal::term::Config::default(),
             ),
         };
         // to_string：SharedString 的 &str 转换要求 'static，字体名是运行时值。
@@ -88,7 +91,7 @@ impl TerminalView {
         };
 
         let initial = WindowSize { num_lines: 30, num_cols: 100, cell_width: 9, cell_height: 18 };
-        let (session, error) = match session::spawn(initial) {
+        let (session, error) = match session::spawn(initial, term_config) {
             Ok((session, mut rx)) => {
                 cx.spawn(async move |this, cx| {
                     while let Some(event) = rx.next().await {

nebula_settings/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "nebula-settings"
+version = "1.0.0"
+license = "GPL-3.0-or-later"
+description = "Shared reader for Nebula runtime user settings (nebula_settings.txt) and theme terminal-color tables"
+publish = false
+edition.workspace = true
+rust-version.workspace = true
+
+# 刻意零依赖：任何壳（winit 旧壳 / GPUI）与任何渲染后端都能免费引用，
+# 不给依赖图带来任何新节点。
+[dependencies]

nebula_settings/src/lib.rs

@@ -0,0 +1,385 @@
+//! Nebula 运行时用户设置（`nebula_settings.txt`）与主题终端色表的共享读取。
+//!
+//! 这是两个 UI 壳同读的权威实现：设置文件的路径解析、键值语义，以及每个
+//! 主题对终端色表的影响（背景替换、浅色主题的前景/ANSI-16 替换、Powerline
+//! 提示符槽位）。设置界面写入的 `nebula_settings.txt` 是运行时用户意图的
+//! 权威来源，优先级高于 `nebula.toml` 的对应字段。
+//!
+//! 同步事实（记录在案）：
+//! - `nebula_app/src/display/ui/theme.rs` 是旧壳体内的既有实现；本 crate 的
+//!   色值与其逐字一致。旧壳按 P4 裁定冻结保留，新 UI 一律读这里；改主题
+//!   色值时两处同步，直到 P3 接入完成后旧壳引用此 crate。
+//! - `nebula_terminal::tty::windows` 里有一份私有的同款路径/键值读取；引擎
+//!   不能依赖 UI 侧 crate（依赖方向是铁律），属有意保留的最小重复。
+//! - `follow_system_theme` 的系统外观联动暂未在此实现（消费方自行处理）。
+
+use std::collections::HashMap;
+use std::path::PathBuf;
+
+/// 设置目录：`NEBULA_CONFIG_DIR` 覆盖（便携/测试隔离，指向目录本身）→
+/// `%APPDATA%\Nebula` → `$HOME/.config/Nebula` → 临时目录。
+/// 与引擎 tty 层、旧壳、注入的 shell 提示符脚本使用同一套解析。
+pub fn settings_dir() -> PathBuf {
+    if let Some(path) = std::env::var_os("NEBULA_CONFIG_DIR").filter(|p| !p.is_empty()) {
+        return PathBuf::from(path);
+    }
+    std::env::var_os("APPDATA")
+        .map(PathBuf::from)
+        .or_else(|| std::env::var_os("HOME").map(|home| PathBuf::from(home).join(".config")))
+        .unwrap_or_else(std::env::temp_dir)
+        .join("Nebula")
+}
+
+pub fn settings_path() -> PathBuf {
+    settings_dir().join("nebula_settings.txt")
+}
+
+/// `nebula_settings.txt` 的键值视图。行格式 `key=value`；键大小写不敏感，
+/// 值两端修剪；空值视为未设置。
+#[derive(Default)]
+pub struct RawSettings {
+    values: HashMap<String, String>,
+}
+
+impl RawSettings {
+    pub fn load() -> Self {
+        std::fs::read_to_string(settings_path())
+            .map(|text| Self::from_text(&text))
+            .unwrap_or_default()
+    }
+
+    pub fn from_text(text: &str) -> Self {
+        let mut values = HashMap::new();
+        for line in text.lines() {
+            if let Some((key, value)) = line.split_once('=') {
+                values.insert(key.trim().to_ascii_lowercase(), value.trim().to_owned());
+            }
+        }
+        Self { values }
+    }
+
+    pub fn value(&self, key: &str) -> Option<&str> {
+        self.values
+            .get(&key.to_ascii_lowercase())
+            .map(String::as_str)
+            .filter(|value| !value.is_empty())
+    }
+
+    pub fn f32(&self, key: &str) -> Option<f32> {
+        self.value(key)?.parse().ok()
+    }
+
+    /// `1/true/yes/on` → true；`0/false/no/off` → false；其余 `None`。
+    pub fn bool_on(&self, key: &str) -> Option<bool> {
+        match self.value(key)?.to_ascii_lowercase().as_str() {
+            "1" | "true" | "yes" | "on" => Some(true),
+            "0" | "false" | "no" | "off" => Some(false),
+            _ => None,
+        }
+    }
+}
+
+pub type Rgb8 = [u8; 3];
+
+/// 主题标识；`nebula_settings.txt` 里 `theme=` 持久化 [`Self::prompt_name`]。
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Default)]
+pub enum ThemeName {
+    #[default]
+    Nebula,
+    SilverLight,
+    SteelDark,
+    LimestoneLight,
+    CoalDark,
+    LinenLight,
+    MossDark,
+}
+
+impl ThemeName {
+    pub fn from_prompt_name(name: &str) -> Option<Self> {
+        Some(match name {
+            "Nebula" => Self::Nebula,
+            "SilverLight" => Self::SilverLight,
+            "SteelDark" => Self::SteelDark,
+            "LimestoneLight" => Self::LimestoneLight,
+            "CoalDark" => Self::CoalDark,
+            "LinenLight" => Self::LinenLight,
+            "MossDark" => Self::MossDark,
+            _ => return None,
+        })
+    }
+
+    pub fn prompt_name(self) -> &'static str {
+        match self {
+            Self::Nebula => "Nebula",
+            Self::SilverLight => "SilverLight",
+            Self::SteelDark => "SteelDark",
+            Self::LimestoneLight => "LimestoneLight",
+            Self::CoalDark => "CoalDark",
+            Self::LinenLight => "LinenLight",
+            Self::MossDark => "MossDark",
+        }
+    }
+
+    /// 主题对终端色表的全部影响（旧壳 `apply_term_colors` 的数据形态）。
+    pub fn term_theme(self) -> TermTheme {
+        // 背景与 is_light 来自各主题 palette()；powerline 为提示符段色
+        // （icon bg/fg、path bg/fg、branch bg/fg、time bg/fg）。
+        match self {
+            Self::Nebula => TermTheme {
+                background: [15, 17, 26],
+                is_light: false,
+                powerline: [
+                    [57, 75, 112],
+                    [192, 202, 245],
+                    [41, 52, 82],
+                    [169, 177, 214],
+                    [47, 79, 79],
+                    [139, 213, 202],
+                    [29, 33, 46],
+                    [100, 116, 139],
+                ],
+            },
+            Self::SilverLight => TermTheme {
+                background: [255, 255, 255],
+                is_light: true,
+                powerline: [
+                    [229, 231, 235],
+                    [55, 65, 81],
+                    [243, 244, 246],
+                    [55, 65, 81],
+                    [224, 242, 254],
+                    [3, 105, 161],
+                    [249, 250, 251],
+                    [107, 114, 128],
+                ],
+            },
+            Self::SteelDark => TermTheme {
+                background: [26, 28, 36],
+                is_light: false,
+                powerline: [
+                    [71, 85, 105],
+                    [241, 245, 249],
+                    [51, 65, 85],
+                    [203, 213, 225],
+                    [59, 82, 73],
+                    [163, 184, 153],
+                    [40, 44, 56],
+                    [148, 163, 184],
+                ],
+            },
+            Self::LimestoneLight => TermTheme {
+                background: [255, 255, 255],
+                is_light: true,
+                powerline: [
+                    [214, 211, 209],
+                    [250, 250, 249],
+                    [231, 229, 228],
+                    [68, 64, 60],
+                    [200, 198, 167],
+                    [41, 37, 36],
+                    [235, 233, 230],
+                    [163, 160, 151],
+                ],
+            },
+            Self::CoalDark => TermTheme {
+                background: [23, 23, 23],
+                is_light: false,
+                powerline: [
+                    [82, 82, 82],
+                    [245, 245, 245],
+                    [64, 64, 64],
+                    [212, 212, 212],
+                    [74, 79, 65],
+                    [181, 181, 166],
+                    [48, 48, 48],
+                    [115, 115, 115],
+                ],
+            },
+            Self::LinenLight => TermTheme {
+                background: [255, 255, 255],
+                is_light: true,
+                powerline: [
+                    [212, 212, 208],
+                    [255, 255, 255],
+                    [229, 229, 223],
+                    [63, 63, 63],
+                    [181, 196, 177],
+                    [45, 45, 45],
+                    [236, 236, 230],
+                    [176, 179, 176],
+                ],
+            },
+            Self::MossDark => TermTheme {
+                background: [30, 33, 30],
+                is_light: false,
+                powerline: [
+                    [75, 85, 72],
+                    [240, 253, 244],
+                    [59, 66, 56],
+                    [220, 252, 231],
+                    [60, 79, 60],
+                    [187, 247, 208],
+                    [42, 47, 42],
+                    [107, 114, 107],
+                ],
+            },
+        }
+    }
+}
+
+/// 一个主题对终端色表的影响。浅色主题额外用 [`LIGHT_FOREGROUND`] 与
+/// [`LIGHT_ANSI`] 替换前景与 ANSI-16（配置的暗底配色在浅底上不可读）。
+/// dim 表与 bright_foreground 有意不动——与旧壳逐字段一致。
+pub struct TermTheme {
+    pub background: Rgb8,
+    pub is_light: bool,
+    /// Powerline 提示符段色，发布到 256 色表 [`POWERLINE_SLOT0`]`..+8`。
+    pub powerline: [Rgb8; 8],
+}
+
+/// Powerline 槽位起点（索引色 16..=23）。
+pub const POWERLINE_SLOT0: u8 = 16;
+
+/// 浅色主题的替换前景（#24292f）。
+pub const LIGHT_FOREGROUND: Rgb8 = [36, 41, 47];
+
+/// 浅色主题的 ANSI-16 替换表（GitHub Primer Light 派生；BrightWhite 刻意
+/// 用灰——纯白会消失在白底终端上）。
+pub const LIGHT_ANSI: [Rgb8; 16] = [
+    [36, 41, 47],    // black #24292f
+    [207, 34, 46],   // red #cf222e
+    [26, 127, 55],   // green #1a7f37
+    [154, 103, 0],   // yellow #9a6700
+    [9, 105, 218],   // blue #0969da
+    [130, 80, 223],  // magenta #8250df
+    [27, 124, 131],  // cyan #1b7c83
+    [110, 119, 129], // white #6e7781
+    [87, 96, 106],   // bright black #57606a
+    [164, 14, 38],   // bright red #a40e26
+    [45, 164, 78],   // bright green #2da44e
+    [191, 135, 0],   // bright yellow #bf8700
+    [33, 139, 255],  // bright blue #218bff
+    [164, 117, 249], // bright magenta #a475f9
+    [49, 146, 170],  // bright cyan #3192aa
+    [140, 149, 159], // bright white #8c959f
+];
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum CursorShapeName {
+    Block,
+    Beam,
+    Underline,
+}
+
+/// 新 UI 消费的运行时设置子集。字段随消费方增长；未设置的键保持 `None`
+/// 让调用方自选回退。
+pub struct RuntimeSettings {
+    pub theme: ThemeName,
+    pub font_family: Option<String>,
+    /// pt（与设置界面一致）。
+    pub font_size_pt: Option<f32>,
+    pub cursor_shape: Option<CursorShapeName>,
+    pub cursor_blink: Option<bool>,
+    pub copy_on_select: bool,
+    pub powerline: bool,
+}
+
+impl RuntimeSettings {
+    pub fn load() -> Self {
+        Self::from_raw(&RawSettings::load())
+    }
+
+    pub fn from_raw(raw: &RawSettings) -> Self {
+        Self {
+            theme: raw.value("theme").and_then(ThemeName::from_prompt_name).unwrap_or_default(),
+            font_family: raw.value("font_family").map(str::to_owned),
+            font_size_pt: raw.f32("font_size").map(|size| size.clamp(4.0, 96.0)),
+            cursor_shape: raw.value("cursor_shape").and_then(|value| {
+                match value.to_ascii_lowercase().as_str() {
+                    "block" => Some(CursorShapeName::Block),
+                    "beam" | "bar" => Some(CursorShapeName::Beam),
+                    "underline" => Some(CursorShapeName::Underline),
+                    _ => None,
+                }
+            }),
+            cursor_blink: raw.bool_on("cursor_blink"),
+            copy_on_select: raw.bool_on("copy_on_select").unwrap_or(false),
+            powerline: raw.bool_on("powerline").unwrap_or(true),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_real_settings_shape() {
+        let raw = RawSettings::from_text(
+            "language=system\n\
+             theme=SilverLight\n\
+             follow_system_theme=0\n\
+             shell=powershell\n\
+             font_family=Maple Mono Normal NF CN\n\
+             font_size=16.3\n\
+             cursor_shape=beam\n\
+             cursor_blink=1\n\
+             copy_on_select=1\n\
+             powerline=0\n\
+             startup_directory=\n",
+        );
+        let settings = RuntimeSettings::from_raw(&raw);
+        assert_eq!(settings.theme, ThemeName::SilverLight);
+        assert_eq!(settings.font_family.as_deref(), Some("Maple Mono Normal NF CN"));
+        assert_eq!(settings.font_size_pt, Some(16.3));
+        assert_eq!(settings.cursor_shape, Some(CursorShapeName::Beam));
+        assert_eq!(settings.cursor_blink, Some(true));
+        assert!(settings.copy_on_select);
+        assert!(!settings.powerline);
+        // 空值 = 未设置。
+        assert_eq!(raw.value("startup_directory"), None);
+    }
+
+    #[test]
+    fn defaults_when_file_content_is_absent_or_junk() {
+        let settings = RuntimeSettings::from_raw(&RawSettings::from_text("theme=NoSuchTheme\n"));
+        assert_eq!(settings.theme, ThemeName::Nebula);
+        assert_eq!(settings.font_family, None);
+        assert!(!settings.copy_on_select);
+        assert!(settings.powerline);
+    }
+
+    #[test]
+    fn theme_names_roundtrip() {
+        for theme in [
+            ThemeName::Nebula,
+            ThemeName::SilverLight,
+            ThemeName::SteelDark,
+            ThemeName::LimestoneLight,
+            ThemeName::CoalDark,
+            ThemeName::LinenLight,
+            ThemeName::MossDark,
+        ] {
+            assert_eq!(ThemeName::from_prompt_name(theme.prompt_name()), Some(theme));
+        }
+    }
+
+    #[test]
+    fn light_themes_replace_foreground_dark_themes_do_not() {
+        assert!(ThemeName::SilverLight.term_theme().is_light);
+        assert!(ThemeName::LimestoneLight.term_theme().is_light);
+        assert!(ThemeName::LinenLight.term_theme().is_light);
+        assert!(!ThemeName::Nebula.term_theme().is_light);
+        assert!(!ThemeName::SteelDark.term_theme().is_light);
+        // 浅色主题终端底全白，背景由主题裁定而非用户配色。
+        assert_eq!(ThemeName::SilverLight.term_theme().background, [255, 255, 255]);
+        assert_eq!(ThemeName::Nebula.term_theme().background, [15, 17, 26]);
+    }
+
+    #[test]
+    fn keys_are_case_insensitive_and_trimmed() {
+        let raw = RawSettings::from_text("  Theme = SilverLight \nFONT_SIZE=12\n");
+        assert_eq!(raw.value("theme"), Some("SilverLight"));
+        assert_eq!(raw.f32("font_size"), Some(12.0));
+    }
+}