feat: add Terminal (ANSI) theme preset that follows the terminal palette (#338)

## Summary

Adds a **Terminal (ANSI)** theme preset built entirely from
`Color::Reset` and named ANSI colors instead of hardcoded RGB. Since
terminals remap already-rendered cells when their palette changes,
terminal-theming tools like pywal recolor spotatui live, with no restart
needed.

Closes #336

## Details

- New `ThemePreset::Terminal` variant wired into the five preset
enumeration points (enum, `all()`, `name()`, `from_name()`,
`to_theme()`). It mirrors the default cyan look using the terminal
palette: Cyan accents, Red/LightRed errors, Yellow hints, Magenta hover,
DarkGray inactive, and `Reset` for text/background.
- No parser changes: `parse_theme_item` and `color_to_string` already
round-trip named ANSI colors, so config persistence, settings-screen
cycling, and live preview all work unchanged.
- New test `terminal_preset_colors_round_trip_through_config` asserts
every color in the preset survives serialize/parse (guards against a
future `Color::Indexed`, which `color_to_string` silently collapses to
`Reset`).
- Changelog entry under Unreleased.

## Testing

- `cargo fmt --all`, `cargo clippy --no-default-features --features
telemetry -- -D warnings`, and `cargo test --no-default-features
--features telemetry` all pass (329 tests).
- Manual: cycle Theme Preset to "Terminal (ANSI)" in Settings (`Alt-,`),
then change the terminal palette (e.g. `wal -i <image>`) and confirm
colors update without restarting.

Author: LargeModGames

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - **Native cross-source play queue**: Press `z` on any track to add it to a native queue that plays across sources (Spotify, Local Files, Subsonic, and YouTube in one FIFO; internet radio is excluded since a live stream is not a finite track). Queued tracks play before the underlying playlist/album context, then that context resumes where it left off. Open the queue with `Shift+Q`: remove the selected item with `x` (rebindable via `remove_from_queue`, default `x`), reorder it with `J`/`K`, or press `Enter` to skip ahead and play it now. The Queue screen also previews what resumes from the underlying context once the queue drains. The queue survives restarts (persisted in `last_session.yml`). Spotify tracks queue through native (librespot) streaming; when you are controlling an external Spotify Connect device instead, `z` keeps the previous Web-API "add to Spotify's queue" behavior ([#206](https://github.com/LargeModGames/spotatui/issues/206)).
+- **Terminal (ANSI) theme preset**: A new theme preset built entirely from the terminal's own ANSI palette colors instead of hardcoded RGB, so terminal-theming tools like pywal recolor spotatui live, without a restart ([#336](https://github.com/LargeModGames/spotatui/issues/336)).
 - **Playlist Folders First setting**: A new `behavior.group_folders_first` toggle (Settings → "Playlist Folders First") lists your Spotify playlist folders at the top of the Playlists tab, above playlists, keeping each group's existing order. Off by default. Handy because folders keep their creation date and otherwise sink to the bottom of the recency-sorted list.
 
 ## [v0.40.1] 2026-07-04

src/core/user_config.rs

@@ -175,6 +175,7 @@ impl Default for Theme {
 pub enum ThemePreset {
   #[default]
   Default,
+  Terminal,
   PookiePink,
   Spotify,
   Vesper,
@@ -192,6 +193,7 @@ impl ThemePreset {
   pub fn all() -> &'static [ThemePreset] {
     &[
       ThemePreset::Default,
+      ThemePreset::Terminal,
       ThemePreset::PookiePink,
       ThemePreset::Spotify,
       ThemePreset::Vesper,
@@ -209,6 +211,7 @@ impl ThemePreset {
   pub fn name(&self) -> &'static str {
     match self {
       ThemePreset::Default => "Default (Cyan)",
+      ThemePreset::Terminal => "Terminal (ANSI)",
       ThemePreset::PookiePink => "Pookie Pink",
       ThemePreset::Spotify => "Spotify",
       ThemePreset::Vesper => "Vesper",
@@ -226,6 +229,7 @@ impl ThemePreset {
   pub fn from_name(name: &str) -> Self {
     match name {
       "Default (Cyan)" => ThemePreset::Default,
+      "Terminal (ANSI)" => ThemePreset::Terminal,
       "Pookie Pink" => ThemePreset::PookiePink,
       "Spotify" => ThemePreset::Spotify,
       "Vesper" => ThemePreset::Vesper,
@@ -262,6 +266,29 @@ impl ThemePreset {
   pub fn to_theme(self) -> Theme {
     match self {
       ThemePreset::Default => Theme::default(),
+      // Deliberately uses named ANSI colors (unlike the RGB rationale in
+      // Theme::default) so terminal-palette tools like pywal restyle the UI
+      // live, without restarting spotatui.
+      ThemePreset::Terminal => Theme {
+        analysis_bar: Color::Cyan,
+        analysis_bar_text: Color::Reset,
+        active: Color::Cyan,
+        banner: Color::Cyan,
+        error_border: Color::Red,
+        error_text: Color::LightRed,
+        hint: Color::Yellow,
+        hovered: Color::Magenta,
+        inactive: Color::DarkGray,
+        playbar_background: Color::Reset,
+        playbar_progress: Color::Cyan,
+        playbar_progress_text: Color::Reset,
+        playbar_text: Color::Reset,
+        selected: Color::Cyan,
+        text: Color::Reset,
+        background: Color::Reset,
+        header: Color::Reset,
+        highlighted_lyrics: Color::Cyan,
+      },
       ThemePreset::PookiePink => Theme {
         analysis_bar: Color::Rgb(255, 255, 255),         // White
         analysis_bar_text: Color::Rgb(165, 30, 100),     // Dark pink
@@ -1956,6 +1983,35 @@ mod tests {
     );
   }
 
+  #[test]
+  fn terminal_preset_colors_round_trip_through_config() {
+    use super::{color_to_string, parse_theme_item, ThemePreset};
+
+    let theme = ThemePreset::Terminal.to_theme();
+    for color in [
+      theme.analysis_bar,
+      theme.analysis_bar_text,
+      theme.active,
+      theme.banner,
+      theme.error_border,
+      theme.error_text,
+      theme.hint,
+      theme.hovered,
+      theme.inactive,
+      theme.playbar_background,
+      theme.playbar_progress,
+      theme.playbar_progress_text,
+      theme.playbar_text,
+      theme.selected,
+      theme.text,
+      theme.background,
+      theme.header,
+      theme.highlighted_lyrics,
+    ] {
+      assert_eq!(parse_theme_item(&color_to_string(color)).unwrap(), color);
+    }
+  }
+
   #[test]
   fn test_reserved_key() {
     use super::check_reserved_keys;